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Fostex A-8 User's Manual

1. 00100988 tior Yo _ 010000028 seoa a 900100978 ziot ZEOLAACSOLIH 601520228 004002 OL NT Lo 0 19900628 00520 NS 7191 FOL 90 10628 2007 M a 3 eee lt a 227 nt 2011000628 101 430 905 n 500100808 010 s UO 580151538 50 5219 M ds 3004005528 6000 wol 1000 02208 05056204 00 000 628 en 461 2205 18 461 get 5102109628 9004002 gt 12 1900 0628 8904 ut ZL 9700 8208 fic wel 0905 1508 220000628 eee 574 1102 0006002529 1007 EL 7700 ocen 9909 000 0 28 9204 530010 SOHTIN n E a 20028 5204 22 ea t OL0v00 028 227 02 0028 wx ADS 20042 2 uR49 L 22602629 209 O LOO OFZ 909 i 4 204000628 204208 BANS ADL aree gt 9 55002629 9202 Ol s 601200 028 8 21000 028 1208 GANS 50 19002628 82074202 f OOD 92131434 tO 1700 0628 508 u COL 0 1000 0228 02076104 4015 1581 GANS ASZ POLY LL 002628 209 0 1900 028 0607440
2. 9007 U x FUNCTION COUNTER DISPLAY A 8LR zi 5 lt 3 3 gt amp 4 TAPE EDIT MAKE RTN EDIT EDIT BRAKE COINSIDENCE s UNCTION COUNTER PCB ASSY 328g 5045 5 M petam 5258 i 8 m o 8 5 3 z 58821 8 NR ON OFF 18 4 8 00 1190 8628 4400 31503 2861 11 2 4 Q rrt ueris ar 210 0 2100 2100 001 2000 9I 2 gt 90 9M 10 13 Pl SI 9 11 H SC 21 62 c 4 4 OL Qv3H 35783 01 18 8 TVNIWH3 L ASSY 90d MS 104109 ASSY 82d 704440 31545 Bld ASSV 82d a mT 11 1 gir id 2 n p n Q T s ea B 5 E 238 300 LYOdSNVHL VL LINN SLOWSY 18 3LOIN3H
3. 25 20 26 27 28 14 13 m 1 THE CONTROLS AND THEIR FUNCTIONS 1 2 3 4 5 6 7 8 Head shield gate The head shield gate is manually operated If the gate is retracted down a short downward push of its top edge will release its lock and the gate fully rise by spring action To retract it the gate is pressed down and will be locked at the limiting position Rewind button REWIND Depressing this button transports tape at high speed from the right reel to the left reel Fast forward button F FWD Depressing this button transports tape at high speed from the left reel to the right reel Stop button STOP All modes of ZERO RIN REWIND F FWD RECORD and PLAY will be cancelled and tape stopped when this button is depressed Play button PLAY Depressing this button puts the recorder in the play mode Record button RECORD a With more than one and up to four RECORD TRACK buttons depressed simulta neous depressing both RECORD and PLAY buttons puts the tracks thus assigned in the record mode b With more than one and up to four RECORD TRACK buttons depressed and with the transport in the PLAY mode simultaneously depressing both RECORD and PLAY buttons puts those tracks thus assigned to the record mode punch in Return to zero position ZERO Depressing this button puts the transport in the rewind mode automatically rewind tape to 0000 of th
4. Flat mounting 3 100 470 8 VOKR 168 3300 4700 4 78 1800 4 40 Electrolytic 2 2uF 50 Ceramic 7052 1032 Electrolytic 100uF 16 Ceramic 7052 1032 EUVB 5 65 PCB ASSEMBLY REGULATOR PCB ASSEMBLY REGULATOR ASSEMBLY No 8273040001 Ref 001 21002 0004 0001 90022003 66 Parts No 8251039000 IC s 82360260 00 8236 0261 00 8236 0262 00 82360263 00 TRANSISTOR 8234 0034 00 DIODE 8234 001957 8234 0007 00 Nomenclature PCB regulator Analog regulator 7818 4 7808 5 78054 7824 250686 Zener WZ240 1N4002 CARBON RESISTORS ROOT 002 8230 0062 21 Flat mounting iW 2200 J Ref No cool C002 C003 0004 0005 0006 6007 C008 2009 C010 Parts Nomenclature CAPACITORS 8232006105 Electrolytic 8232 0051 07 8232 0064 76 4 8232 0051 07 d 8232 0061 05 9232 0031 07 8232 0061 05 8232 0031 07 8232 0061 05 8232005107 e 50V 5 100uF 35V SMVB 47uF 50V SMVB 100 357 SMVB luF 50V 5 100uF 16V 5 luF 50V 5 100uF 16V 50V SMVB 100uF 35V 5 PCB ASSEMBLY RECTIFIER RECTIFIER PCB ASSEMBLY ASSEMBLY 8273039000 Ref No Nomenclature A D001 A 0001 003 A D004 C001 2002 C003 04 C005 C006 C007 Parts No 8251040000 DIODES 8234001602 82
5. HEAD Fig 6 12 3 Adjust the Azimuth and Phase Adjusting Screw for maximum reading on all eight VU meters of the recorder Then connect the vertical input of the oscilloscope to TRACK 1 output and the horizontal input to one among TRACKS 2 8 set the oscilloscope to mode to obtain a lissajous waveform to check the phase GA gt Trace for vertical input alone Trace for horijontal Unequal levels input alone If the trace length between 1 and 2 are not the same it means that the two inputs are not of the same level Correct for equal lengths by the oscilloscope controls If the playback head azimuth is out of alignment the following patterns will result a 74 small misalignment 30 A larger error 90 A big one 180 Perfect azimuth out phase outof phase out of phase Q in phase Fig 6 13 37 4 5 As a result of phase check with a 10KHz signal the adjustment is finished if difference in phase is less than 90 between tracks and azimuth adjustment is at the best point i Check the playback frequency response of each channel by playback of the Frequency Response section of the Reproduce Alignment Tape The recorder VU meters can be used for this check but if a more accurate measurement is necessary the level meter is plugged one by one into the recorder rear panel 1 9 8 OUTPUT jacks and the levels measured here The normal playback frequency response sh
6. button is depressed as U9 2 pin will be connected to zero volt via D32 On the other hand an level is applied to 04 7 5 input pin via inverter U7 04 is a JK flip flop and pins Q and K are set to when is set to H At the instant the counter display changes from 0001 to 0000 the emitter of 03 is held at zero volt for a length of about 200 400msec after which 03 switches on U9 6 STP goes to L and U9 goes to STOP mode The L output from the counter returns to after about 200 400msec plied to U4 3 C input and the Q and K pins returns to L level 04 4 input is the reset pin and the ZERO is reset by the REWIND F FWD STOP PLAY and SHUT OFF signals COIMCICEMCE 12 4 3 REMOTE PUNCH IN OUT REMOTE PUNCH IN OUT A latching type foot switch is plugged into the REMOTE PUNCH IN OUT phone jack on the rear panel Each time the foot switch is depressed C15 is repeatedly charged dis charged producing waveforms shown below These signals are shaped by Ul and then input to the exclusive OR gate 02 10 When input pins 8 and 9 are in combinations of L and levels an level is obtained from its output pin 10 whose waveform is shown below FOOT SWITCH Fig 4 2 06 is a delayed flip flop which outputs signals shown below upon receiving play mode level from 03 10 and the signal from the fo
7. 3 15 3 3K 5 6K 6 8 metal 2 2 1 68 5 1 5602 3 9KQ 9 1 2 2Xn 102 4 7KQ 33KQ 100KG 4 7 2 200 22Kn 27 8 2 5 6Kn Vertical mtg 2 7 22 0 56 93 Ref R171 RU2 R173 R174 R175 R176 R177 8178 C102 C103 C104 0105 396 C107 C108 C109 0110 112 113 C114 C115 C116 C117 C118 C119 C120 C122 C123 124 125 126 C127 C128 C129 C130 C13 C132 C133 C134 C135 C136 C137 C138 C139 C140 94 271 272 273 274 275 276 277 278 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 lt 8230 0041 04 82300043 33 82300041 04 82300043 61 8230 0043 33 8230 0041 04 82300042 73 82300043 34 CAPACITORS 8232 0061 05 8232 0264 72 8232 0031 06 8232 0264 73 8232 0031 06 8232 0182 24 8232 0024 77 8232 0263 33 8232 0261 04 8232 0263 33 8232 0261 04 8232 0033 36 82320711 06 8232 0351 03 8232 0054 75 82320512 20 8232 0054 75 8232 0042 26 82320054 75 8232 0041 06 82320261 02 8232 0511 01 8232 0031 07 8232 0851 05 8232 0342 71 8232 0033 36 8232 0261 53 8232 0512 20 8232 0031 06 8232 0061 05 8232 0514 70 8232 0303 33 8232
8. wu 2 5 1 m aio oes Pagou ssatun 5 WP THNGZ 13111 sted aj po 000109428 02 SOLN 40629 WIN 0060209628 02 OLN v 9100023 592 020008 299900028 122 1218 2 UNO a u 289900678 292 2118 2250008 02100218 00 0008628 02 mem sd MA IAL n u 1 ONCE n 009000129 612 b 002104 S aD 95 29 540006289 092 ORLY 595 29535000620 812 9114 SAd OSL W 005800628 902 1020 26000528 662 mot 8015000620 LLZ 4113 SAd OSL 0046004828 90144010 UNSL 2213298 090000628 852 BELA 008 19880088 912 ILIY 18 ampjiidue d l A04 0010011928 1 E 34177 ON 51494 OK j 1 ON 394 ON 71395 20 0280 5128 ASSY 15 4592 18 17883554 824 313114 4 any 2 7 4 J T Xo uq eed Bosse da ders er Z XD j 5 w t AN Ref R161 8162 8163 R164 R165 8166 8167 8168 8169 R170 17 R172 R173 R174 R175 R176 R177 R178 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 Parts No 8230 0041 02 8230 0042 00 8230 0042 23 82300042 73 8230 004
9. 21 Transport function remote connector REMOTE TRANSPORT Remote operation of the transport function controls is possible by connecting the optional Model 8030 Remote Control Unit 22 Punch In Out remote jack REMOTE PUNCH IN OUT This jack is used for punch in out of the recording foot switch Any one button among the four RECORD TRACK selector buttons is depressed and the trans port put in the PLAY mode Then if the foot switch is depressed the previously selected track goes to the record mode if the foot switch is depressed again the record mode is cancelled and the transport goes to the record ready play mode With none of the RECORD TRACK selector buttons depressed and the recorder in play mode depressing the foot switch will make the record indicating LED to blink indicating that the recorder is in the record ready state while in play mode When any one of the RECORD TRACK selector button is depressed under this condition the track of the depressed button will go to the record mode but will be cancelled returning to the record ready state when the foot switch is depressed again One word of caution the foot switch can neither punch in nor out when the transport is put in the record mode by the control panel PLAY and RECORD buttons 23 Input jack INPUT 24 OUTPUT JACKS OUTPUT These 8 jacks carry the output from tracks 1 through 8 of the recorder With the INPUT MONITOR selector and RECORD TRACK selector but
10. ModeIA SA 8L R 8 TRACK RECORDER REPRODUCER Service Manual NOTICE This Service Manual applies to the A 8 Series not the A 8LR Series with serial numbers from and after those listed below UK AUS versions 0700464 FCA versions 0201667 EUR versions 0601195 DM versions 1000632 The content is slightly different for those with serial numbers younger than the above A separate document Order No 8288010101 is available for the revised section of the manual The Service Manual for A 8LR starts from page 71 FOSTEX TABLE OF CONTENTS 1 INTRODUCTION Elec x Durst ten ua uds us 3 2 6 4 3 THE CONTROLS AND THIER FUNCTIONS 6 4 FUNCTION OF THE CONTROL 11 5 ROUTINE MAINTENANCE 22 6 SPECIAL MAINTENANCE 24 7 EXPLODED VIEW PCB ASSEMBLIES AND PARTS LIST 43 MODEL A 8LR SERVICE MANUAL 71 1 THE CONTROLS AND THEIR FUNCTIONS 73 2 SPECIFICATIONS u nm aon uwa ane 78 6 SPECIAL MAINTENANCE 79 7 PCB ASSEMBLIES AND PARTS LIST 87 5 Adjust
11. 75KQ 7 5 72 100K2 4 7 4 70 8200 2 78 100Ka 4709 Ref No R113 83146116 81174118 R119 R120 R12 2122 R123 8128 R125 126 127 R128 8129 R130 R131 R132 R133 R134 8135 R136 R137 R138 R139140 R141 R142 R143 R144 8145 R146 147 8148 R149 81504151 8152 R153 81544157 8158 5159 R160 R161 R162 R163 R164 R165 R166 R167 R168 R169 R170 R171 R172 R173 R174 81755177 R178 Parts No Nomenclature 8230004474 Vertical mounting 4N 470K 82300044 73 82300041 02 82300046 82 8230004683 82300041 04 82300044 74 8230004392 82300046 82 82300046 83 82300044 73 8230004753 8231003223 82300041 53 82300046 82 82300041 02 8230 0044 33 82300042 72 82300290 30 82300041 02 8230 0044 73 8230 0041 03 82300041 02 82300041 02 82300045 63 82300041 04 82300044 74 82300044 73 82300046 83 82300044 73 82300041 02 82300041 04 8230 0046 82 82300044 73 82300048 23 8231003223 8230004153 82300046 82 8230 0041 02 82300044 33 82300290 30 8230004272 8230004102 82300041 03 82300041 02 82300041 01 8230004222 82300041 03 8230004102 8230004104 dag s 6 8KQ n 5 d 10068 470 3 9 0 6 8 n n 68K a 7 75ka VR carbon flat mtg 8 22 0 Verti
12. 140 0142 C148 251 252 240 241 242 248 8232 026332 223 8230004682 Vertical mtg 6 8 0 Deleted PES 50V 3300pF 5 AMX Deleted PCB ASSEMBLY REMOTE CONTROL REMOTE CONTROL PCB ASSEMBLY ASS Y No 8273086000 Ref Parts No Nomenclature 8251 1020 00 PCB remote IC s 0001 8236 0006 00 Digital CMOS 14012 CARBON RESISTORS 0014008 82300061 04 Flat mtg 100Kn 1 CAPACITORS 0014003 8232 0351 03 Ceramic 1000pF 50V YF 95 FOSTEX FOSTEX CORPORATION 512 MIYAZAWACHO AKISHIMA TOKYO JAPAN FOSTEX CORPORATION OF AMERICA 1543 BLACKBURN AVE NORWALK 80650 U S A PRINTED IN JAPAN JAN 1983 8288 057000 RECORDER A Series A 8LR ASSY 82d N31Nn02 NOULONDd ASSY 824 pex VEM 9 NYH2 4 9 2 NYMO 1 1 mid wh 2 52 L 5 ASSV 82d 1 E 5 ASSY 824 74510 T3NNVHO Ano Ni HONnd 31038 4 20 7 7 0 ASSV 834 W31SAS Fo ASSV 82d 7338 MOLOM anzav I ew ASSV 854 WNIWS3 L SOLOW 7334 X assy 4 31411938 CHANNEL SELECTOR OF CONNECTOR BOARD A 8LR 0104 08154084 90041 22403 DISPLAY x SWITC
13. 330X 390 9 12K 8 2 0 100K2 2002 15K 150 0 5609 5 6KQ 33KQ 22Kn 5 6 Ref Ho 8122 R123 R124 R125 R126 R127 R128 R129 R130 R131 R132 R133 R134 6135 R136 R137 R138 R139 R140 8141 8142 R143 R144 R145 R146 R147 R148 R149 R150 R151 8152 8153 R154 R155 156 R157 R158 R159 R160 R161 R162 R163 R164 165 8166 R167 R168 R169 R170 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 Parts 82300041 03 8230 0046 82 8230 0041 01 8230 0046 82 8230 0045 62 8230 0041 03 8230 0042 21 8230 0042 73 82300043 31 82300044 73 8230 0041 03 8230 0043 91 8230 0043 94 8230 0043 32 82300041 53 8230 0043 32 8230 0045 62 8230 0041 02 8230 0046 82 8230 0232 22 8230 0046 83 8230 023512 8230 0045 61 8230 0043 92 8230 004912 8230 0042 22 8230 0041 00 8230 0041 23 8230 0044 72 8230 0043 33 8230 0041 04 8230 0044 72 8230 0041 83 8230 0042 02 n 8230 0041 02 8230 0042 00 8230 0042 23 8230 0042 73 8230 0048 22 8230 0045 62 8230 0041 05 82300042 72 82300042 23 82300045 63 Deleted Nomenclature 6 8 1000 6 8 5 6KQ 2200 27 Vertical mtg 3300 47KQ 3900 390
14. 873 p 4 7 TAPE COUNTER DETECTING CIRCUIT AND MOTION SENSING CIRCUIT Rotation of the left side reel table is detected by two photo interrupters and their outputs fed to the counter section These outputs serve as the count pulse and up down signal The signals from the two photo interrupters are converted as shown in the Signal Timing Chart of Fig 4 7 and applied to the counter section the count pulse and up down signal 18 BC er2 L 24 fin mnm jJ JL 2 L U EFL 03 4 1 41 f nh n 96 12 UP DOWN l n LIT u 05 10 HIGH SPEED UP DOWN PULSE High spsed L Law soam Fig 4 7 4 8 COUNTER SECTION Ul is the P MOS type tape counter LSI which contain both a counter circuit and display driver Display is of the static type UP DWN Input pin for selecting up count or down count of the counter An H level must be applied to this 01 12 pin for up count function As shown by the timing chart in Item 4 7 above these outputs go to H level in the PLAY or F FWD modes and thus Ul goes to up count mode In the ZERO or REWIND modes level is applied to 01 12 and the counter thus g
15. A 25 26 27 50 Parts 82200604 00 8270035000 8270036000 8270037000 8248003000 8273012000 8273043000 8253029001 8253029002 82530300 02 8270038001 8273048000 82600321 00 82600331 00 8220048000 8212028000 8270040000 8270031000 8245017000 8273041000 8276 0030 00 82760040 00 82760050 00 8276 0060 00 82760070 00 8276 0080 00 8207 0002 09 8207 0002 15 8207 0002 07 82200570 00 82700040 00 8245 0300 00 8270034000 8256008000 8256009000 8256010000 8256011003 8216027000 82200451 00 Nomenclature Chassis 8 4 PCB assembly control switch PCB assembly display Control pot Meter PCB meter PCB assembly group switch Switch power DM 4 USA CND EUR Function counter assembly PCB assembly switch Chassis assembly side 1 n R Bracket Guide PCB PCB ass y connector board 8T PCB ass y regulator 8T Connector jack RCA black 8P Connector ass y transport remote Cord power USA HYDRO EUR z UK AUS Bushing SR 4K 4 EUR UK AUS SR 5P 4 HYDRO SR 4P 4 UL CSA Back panel 87 Rivet plastic No 980 nctr jack phone mono 36 7625 System contro assembly Sparkiller DM UL CSA Capacitor SEMKO Cover switch A AUS Heat sink power ALL EXPRODED VIEW D in 6 2 TAPE TRANSPORT ASSEMBLY EXPLODED VIEW SYSTEM CONTROL PCB ASSEMBLY ASSEMBLY No 8273033000 Ref No
16. Ceramic YF 50Z 103 Electrolytic 16 l uF SMVB Ceramic YF 50Z 103 Electrolytic 16V 10 Ceramic YF 50Z 103 Electrolytic 16 10 Ceramic 507 103 Electrolytic 16V 10 5 22uF Ceramic 507 103 Electrolytic 25V 10uF 5 5 35V 4 7uf Mylar 50V 0 J Electrolytic 16V 47uF SMVB Polypropylene 1007 390 J Deleted Electrolytic 25V 10uF LRVB 470uF 5 Deleted Electrolytic 50V luF SMVB 2 2uF 5 SMVB 5 8 Parts Nomenclature MISCELLANEOUS 8242 053000 Inductor 150 8242 0090 00 bias 8245 049019 jack 19 5256 194 8245 0070 05 5 o SP 5129 05A Deleted 8245 001005 Cnctr jack 5045 054 8245 0010 45 BL 5045 05A 8245 0010 07 o 5045 07 8245 0010 02 5 5045 02 8245 001025 SP 5045 05 8245 0010 05 7 5045 05 8245 0500 00 9 RCA QP 8276 002004 Wire jumper 10mm pitch 180 8276160017 Cable flat 3 cond 170mm YOLIJJNNOI anwy 2421749 SOS e gt ui n T ZA HUI 2 m 18 H3lJlldWV d d ASN R P AMPLIFIER PCB ASSEMBLY 87 19 8 Ass y 8273 0820 OY Ref Parts No Nomenc ature 8251 1001 00 PCB R P IC s ifier 8T 1101 203 8236027600
17. Model 8155 U S A Hewlett Packard Model 204C or equivalent Range 0 lMHz sensitivity O lVrms impedance gt 1MQ lt 25 General purpose frequency analyzer Range 80dB 40dB impedance gt 1M2 lt 25pF Example HP400GL General purpose For reproduce alignment Fostex P N 82660100 MRL 21J103 Magnetic Reference Lab All specs are identical with 82660100 except for the reference fluxivity which is 200nWb m and thus its reproduce output level will be 2dB lower BASF Calibration Tape DIN 45513 2 All specs are identical with 82660100 except for the reference fluxivity which is 320nWb m and thus its reproduce output level will be 1 5dB higher For wow flutter measurement Fostex P N 82260080 STL 453 1 Standard Tape Lab Ampex 357 or Scotch 227 is recommended 6 2 DISMOUNTING OF MAJOR COMPONENTS Depending on the extent of special maintenance you may have to remove the bottom cover trim panel and furthermore dismount major components inside For the sake of efficient maintenance please follow the procedures below Should it be difficult to fully understand the procedures please refer to the EXPLODED VIEWS 1 Bottom cover Fig 6 1 The record reproduce amplifier can be adjusted to a certain extent by removing only the Bottom Plate but for Dolby level calibration and bias trap adjustments the Bottom Cover must be removed The bottom cover can be removed by unscrewing four screws A on the bo
18. Parts No Nomenc lature Ref No Parts No Nomenclature 8251 0362 00 PCB system control DIODES Ic s 0001462 8234001800 150 0001 8236 002901 Digital MC14050B 0063065 8234000700 114002 flat mounting 002 82360032 01 MC140708 0066069 8234001800 150 0003 8236 0040 01 MC140818 00704071 8234000700 1N4002 U004 82360018 01 140278 00724074 8234001800 150 1005 8236 0001 01 MC14001B 0006 8236000701 MCI4013B CARBON RESISTORS 1007 8236003101 MCI4069U8 R001 8230004472 Vertical mounting i 4 7 1008 82360005 01 MCI4011B 8002 82300041 03 u n 1009 8236 0190 00 6251 R003 8230004104 1006 OTO 8236 0028 01 MCT4049UB 8004 8230004474 10114012 8236025902 Analog LM324N ROOS 006 8230004473 8007 82300044 72 4 70 R008 82300041 03 Q001 009 82340002 03 2SC1815GR 8009 82300044 70 470 0010 8234000303 2SA1015GR 8010 8230004472 i 4 7K 0011 012 8234000203 256181568 8011 82300044 70 x 470 0013 8234000303 2SA1015GR 80124013 8230004223 0014 8234000203 2SC1815GR 8014 82300044 72 4 79 0015 8234000303 25 10156 8015 82300041 01 i 1000 9015 8234000203 2SC1815GR 8016 82300044 70 479 40174018 8234000303 2SA10156R ROI 82300041 04 n Q019 8234000802 250880 R018 82300044 74 470 8234000502 258834 8019 82300044 72 5 4 7 0021502
19. the LED of the channel corresponding to the depressed button will glow continuously With none of the four RECORD TRACK buttons depressed and while the transport is in the play mode record ready state all four LED s of channels 1 4 or channels 5 8 selected by the GROUP select button will blink under this condition if any one or up to four of the RECORD TRACK buttons correspond ing to the channels of the blinking LED s are depressed the LED of the de pressed channel only will glow continuously and the other LED s will be ex tinguished If any RECORD TRACK button is depressed during ZERO RIN REWIND F FWD PLAY or STOP modes the LED of the depressed channel will blink Cue lever CUE The lifter mechanism lifts the tape away from the head in the ZERO RIN REWIND and F FWD modes The cue lever is provided to allow tape cueing when the tape is thus lifted from the head Shifting the cue lever moves the lifter pins toward the head and the tape will touch the head 19 Power switch POWER AC power is applied to the unit and the VU meters lighted when this button is depressed The capstan motor will not rotate unless the takeup reel side tension arm is up in other words unless the shut off switch linked to the tension arm is on but the capstan motor will rotate even though the tension arm is down only when in the EDIT mode 20 Reel clamper The reel is secured to the reel turntable by CW rotation of this clamper
20. the oscilloscope probe is hooked to TP 104 and the probe ground clip to GND nearest to 105 Put TRACK 1 in the record mode and check bias leakage at TP 104 It is normal 38 if the voltage is 1 1V it is off spec check frequency 100 2 0 5KHz of the bias erase master oscillator before rotating the center core of 0108 to adjust bias leakage 6 4 5 Erase current adjustment In adjusting the erase current put the track to be adjusted in the record mode To adjust TRACK 1 for example hook the hot side of the oscilloscope probe to TP 103 located near relay 101 and the ground clip of the probe to GND pin in front of the REP EQ pot R313 Set the core of L 103 so that voltage at TP 103 is 1 7 The test point for TRACK 2 is TP 203 located near relay L 201 The GND pin to be used is located left of the REP CAL pot R324 erase current is adjusted by the core of L 203 6 4 6 Bias current adjustment The track of which bias current is to be adjusted is put in the record mode To adjust TRACK 1 for example hook the oscilloscope probe hot side to TP 102 located near connector J 101 and the ground clip to the GND pin Then set the BIAS LVL pot R317 47 at approximately 450mV P P For an accurate adjustment load a blank tape Ampex 457 Scotch 227 on the recorder record a test signal set the NR switch to INT and trim the BIAS LVL pot so that the overall frequency response is within b
21. 017000 Module OSC LR 100KHz TRANSISTORS 0001 8234 0003 03 254101568 0002 005 8234 0002 03 2SC1815GR 9006 82340037 02 25 2655 9007 8234 0038 02 25 1020 0008 8234 0003 03 25 101568 DIODES 00011913 8234 0035 00 150 FVS 014 8234 0007 00 184002 0015 8234 0035 00 150 FYS 1001 2002 2003 8004 ROOS R006 007 ROOB 009 ROTI R012 R013 R014 8015 ROE R017 R018 RG19 8020 8021 R022 R023 R024 8025 8026 8027 CARBON RESESTORS All resistors iW 558 unless otherwise noted 8230 0044 72 Vertical mounting 4 7 0 8230 0001 03 8230 0001 03 8230 0042 43 8230 0041 04 8230 0003 33 8230 0001 04 8230 0004 72 8230 0001 03 8230 0001 04 8230 0002 43 8230 0001 04 8230 0003 33 8230 0001 04 8230 0004 72 8230 0001 03 8230 0001 04 8230 0002 43 8230 0001 04 8230 0003 33 8230 0001 04 8230 0004 72 8230 0001 03 8230 0041 04 8230 0042 43 8230 0001 04 8230 0003 33 100 24 100 0 BIKR 00 4 7 100K2 24KQ 33kn TOOKR 4 7KQ 100K2 2452 33 4 70 100 24KQ 100 33KQ Ref No Parts No Nomenclature R028 8230 0001 04 Vertical mounting 100 0 R029 8230 0004 72 4 7KQ RO30 8230 0001 03 10 R031 8230 0001 04 100 8 8032 8230 0002 43 24 8033 8230 0001 04 a 100 R034 8230 0003 33 4
22. INT EXT switch on the recorder front panel to INT 6 4 2 Calibrating the Dolby decode mode 1 Set the NR INT EXT switch on the recorder front panel to EXT and switch off all RECORD TRACK buttons 2 Playback the Reference Level Section of the Reproduce Alignment Tape 3 Beginning adjustments from TRACK 1 CHAN 1 connect a level meter to test point TP 101 located near 0106 upon the CHAN 1 PCB of the record reproduce amplifier and adjust REP CAL R314 10 so that the level is 390mV 4 After these adjustments connect the level meter to the recorder rear panel OUTPUT 1 jack and check that the level is 10 0 3V 1 5 After check of the OUTPUT jack level confirm that the meter reading is 0 VU 1 VU If the reading is not 0 VU 1VU repeat the adjustments in the previous section Item 5 6 Calibrate tracks 2 8 CHAN 2 8 by the same procedures for TRACK 1 above 7 On completing the above adjustments return to INT the NR INT EXT switch on the recorder front panel 6 4 3 Adjusting the reproduce frequency response 1 Set the NR INT EXT switch on the recorder front panel to EXT and switch off all 36 RECORD TRACK buttons 2 Playback the Head Azimuth and Frequency Response sections of the Reproduce Align ment Tape The Azimuth and Phase Adjusting Screw is adjusted for this alignment as shown in Fig 6 12 Height Adjusting Screws 7 Ajimuth and Phase Adjusting Screw ERASE HEAD
23. LED selected by the RECORD TRACK button is connected to OV and that LED will blink Blinking of the GROUP LED 1 4 or 5 The transport goes to the record mode if both the RECORD and PLAY buttons are Simultaneously depressed Then if none of the RECORD TRACK button is depressed all four LED s for tracks 1 4 or 5 8 either of which is selected by the GROUP button will blink The 8V supply is applied to the LED through Q5 which is switched on by the record mode L level from the transport control circuitry 06 is switched by the applied to its base and an is thus applied to the base of Q9 but as the emitter of Q9 is connected via D5 to the collector of Q4 which is constantly switching on and off the four LED blinks This blinking of all four LED s clearly indicate which group of tracks have been selected and when any one of the RECORD TRACK button is depressed while in this state the base of Q9 drops to zero volt thus switching it off and the 8V flows through D5 LED 013 or 014 015 016 then to zero volt Therefore the led the selected track s only is lighted and the other blinking LED s will go off Constant lighting of the LED The LED will change to constant lighting when any one of the RECORD TRACK button is depressed during the RECORD mode or when this order of depressing the button 20 is reversed 4 10 RECORD INDICATION The RECORD indicating LED either blinks or lights con
24. R076 8230 0001 02 4 3 IKR R077 8230 0001 03 10K2 078 8230 0001 04 5 gt l00ko 8079 8230 0002 20 5 229 87 Ref 8080 8081 082 RO83 8084 8085 8086 087 100 R101 002 003 C004 C005 006 C007 C008 009 coll C013 0014 2016 C017 018 C019 C020 02 C022 6023 0025 C026 032 C033 C034 C035 C036 C037 C038 C039 C040 6041 C042 055 0056 0057 012 015 024 88 Parts 8230 0005 62 8230 0001 09 8230 0005 62 8230 0041 04 8230 0043 94 8230 0044 73 8230 0041 03 5 8232 0351 03 8232 0031 06 8232 0351 03 8232 0031 06 8232 0351 03 8232 0031 06 8232 0351 03 8232 0031 06 8232 0351 03 8232 0031 06 8232 0351 03 8232 0031 06 8232 0351 03 8232 0031 06 8232 0351 03 8232 0031 06 8232 0032 26 8232 0351 03 8232 0041 06 8232 0054 75 8232 0261 03 8232 0034 76 8232 0031 06 8232 0313 91 8232 0721 06 8232 0044 77 8232 0061 05 8232 0062 26 Nomenclature Ref No Vertical mounting 5 6KQ J ES E m 3 100 8 j s 390KQ 2001 08 oos 2003 Deleted 0010 Vertical mounting TOKQ 2011 4012 507 103 4013 Electrolytic 16V lOuF SMVB 3014 015 507 103 9016 Electrolytic 16V lOuF SMVB 9017 502 103 90181021 Electrolytic 16 lOuF 5 Ceramic 507 103 Electrolytic 16V lOuF 5
25. and the re maining channels will be for tape monitor When the PLAY and RECORD buttons are simultaneously depres sed channels 2 and 3 will go to the record mode and also in the input monitor mode for these two channels only Head assembly Counter display Revolutions of the supply reel table is detected by two photo interrupters and shown on a 4 digit display Reset button The counter display reset button which clears the display to 0000 Edit button EDIT The EDIT switch is provided to facilitate precise splicing of tape after remov ing an unwanted section of tape When this slide switch is set to OUT upper side the transport will be in the normal operating mode and when set to IN lower side it will be in the EDIT mode When in the EDIT mode the transport will not go into any other mode except PLAY and STOP In the EDIT mode the shut off switch linked to the right tension arm will be ineffective and therefore the capstan motor will rotate upon switching on the power switch and the takeup reel remain stationary when the PLAY button is de pressed In this case the mechanical brakes will be released but no power is applied to the takeup reel motor and the takeup reel can be rotated easily by hand If EDIT is switched ON during the PLAY mode tape will stop but if the PLAY button is depressed again the tape will be transported at the play speed but will not be wound by the takeup reel If EDIT is switched OUT under thi
26. check the meter reading The MONITOR switch must be at TAPE It is in normal condition if the meter reading 15 0 VU 31 5 VU If it is off spec correct by adjusting REC LVL R315 5 Do the same on the remaining tracks 2 3 and 4 For adjusting tracks 5 6 7 and 8 set GROUP select to 5 8 and follow the same procedures as for TRACK 1 6 4 8 Overall frequency response 1 With the front panel NR INT EXT switch at EXT and under the measurement setup of the previous Section 6 4 7 apply signals from 40Hz through 18 2 at 104 0 3V to the recorder INPUT jack and set the NR switch to INT To adjust TRACK 1 for example apply the signal to INPUT 1 and plug in a level meter to OUTPUT jack 1 Put TRACK 1 in the record mode to record a certain length of the signal rewind it to the start and playback the tape It is in good normal condition if the frequency response in reference to 400 2 is within 3dB and 3dB If it does not fall within spec in the high frequency region correct it by a slight rotation of REC EQ pot R316 lK B 2 Check and adjust the remaining tracks in the same way 6 4 9 Overall S N measurement 1 Set the front panel NR INT EXT switch at INT 2 Upon completing checking up to Section 6 4 8 apply a 400Hz 10dBV 0 3V sig nal to the rear panel INPUT jack 1 example for track 1 record the signal onto a blank tape then without stopping the tape unplug the oscillator connected to the INPUT jack and further re
27. is depressed and the transport is in the record mode By the level of 07 10 03 11 goes to and the from 03 10 applied to Ul 2 makes output Ul 3 go to L which is the encode mode signal After a cer tain delay introduced by the integration circuit of R14 and C5 01 4 goes to L which makes both Ul 11 and Ul 10 go to L level When either U7 8 or U7 9 goes to H level U7 10 will go to H then as Ul 4 first goes to 01 11 goes to bias off then after a delay intro duced by R14 and C5 Ul 10 goes to H record relay off and after another delay 21 R16 and C6 01 3 goes decode mode 06 4 is the for controlling the master bias and its output goes to level when one track goes to the encode mode and to L level when all tracks are put in the decode mode 4 12 MONITOR SELECT CIRCUIT If the MONITOR selector is set to INPUT when the record reproduce amplifier is in the decode reproduce mode that channel only goes to the ENCODE record mode and the monitor output is changed from reproduce output to record input When MONITOR select 1 is set to INPUT an L level is applied to U3 8 and thus U3 10 goes to L which is applied to Ul 2 Under this condition if the GROUP select is at GROUP 1 v 4 then 08 1 will be at L and CHAN 1 will go to the ENCODE mode If the GROUP select is at GROUP 5 8 U6 9 will be H and thus U6 10 also at to make CHAN 1 go to the DEC
28. the pressure will greatly change with only a slight shift in position re position the solenoid in small increments The pressure will increase by moving the solenoid in the direction away from the capstan motor After obtaining optimum pressure securely tighten the screws and make a final re check of the pressure Spring Loosen for solenoid adjustment A CAPSTAN PINCH ROLLER SPRING SCALE 90 B Fig 6 8 31 2 32 Adjust position of the solenoid limit so that the gap between capstan shaft and pinch roller is approximately 4mm when the solenoid is not actuated Limit is adjusted by loosening the mounting screw A then sliding the limit until the proper gap is obtained Brake torque Brake torque is applied mechanically Pressure is set by the variable spring force While making these measurements and adjustments be careful not to bend the brake bands As brake torque will change after cleaning brake drums and brake shoes should be cleaned only when absolutely necessary If cleaning is required use alcohol After cleaning operate the machine for a month of normal operation before performing the procedures below Brake adjustments are made with NO power to the equipment a Place an empty 2 hub reel on the left reel table and fasten one end of a 30 length of twine to the reel anchor b Wind several turns of twine CCW around the hub and attach a suitable spring scale to the free end of
29. the twine c Take reading only when the reel is in steady motion since the force required to overcome static friction will produce a false excessively high initial reading d The reading should be 28 5 42 0 in oz 800 1200 g cm Spring t Formula for torque calculation in oz gcm Rx W Whereas R Radius of hub in cm W oz gm Fig 6 9 3 If adjustment is required hook the spring to the next hole Torque will increase as the spring is successively hooked to holes in the outward direction The adjustment of the right brake is the same with the exception that rota tions are clockwise wind string CLOCKWISE around reel hub The torque should be the same as for the left brake Tape tension adjustment procedures Tape tension is adjusted in the PLAY mode only and are fixed for the F FWD and REWIND modes Tape tension is determined indirectly by measuring the torque supplied by the supply and takeup motors AKEUP TORQUE Fig 6 10 Back tension adjustment procedures 1 2 3 4 5 6 7 8 9 Block the shut off arm in the ON position Place an empty 7 reel on the left reel table Manually rotate the reel and wind several turns of twine around the hub Attach spring scale to other end of the twine Place deck in the PLAY mode Pull the scale away from the reel against the motor torque with a smooth steady motion Read the scale wh
30. 0264 72 8232 0301 03 8232 0182 24 8232 0033 36 8232 0321 51 Nomenclature 33K 3600 27 330 0 Electrolytic 50V luF 20 SM PES 0 0047uF 5 AMX Electrolytic 167 20 SM PES 50V 0 047uF 5 SM Electrolytic l6V lOuF 20 SM 50V 0 22uF 20 u 104 470uF 20 SM PES 50V 0 033uF 5 AMX o O luF 5 AMX 0 033uF 5 AMX o 0 luF 5 AMX Electrolytic 16V 33uF 20 SM Deleted Electrolytic Ceramic 50V Electrolytic Ceramic 50V 22 10 SL Electrolytic 35V 4 7uF 20 SM 25V 22uF 20 SM 2 35V 4 7uF 20 SM 5 a 254 20 SM PES SOV 1000 5 AMX Deleted Ceramic 100 10 SL Electrolytic 16 100uF 20 SM 50V LR BP Ceramic 50V 270 10 YB Electrolytic 16V 33uF 20 SM deleted PES 50V O 0l5uF 5 AMX Ceramic 50V 22pF 10 SL Electrolytic 16V l uF 20 SM SOV TuF 20 SM Ceramic 47 10 SL PPR 1004 0 033uF 2 APS PES 507 4700pF 5 AMX PPR 1007 0 014 2 APS Electrolytic 50V 0 22uF 20 l6V 33uF 20 SM Ceramic 50V 150 5 16V 10 20 LR VB 0 0luF YF 35V 4 7uF 20 SM Ref No 141 241 142 242 143 243 C144 244 C145 245 C146 246 C147 247 C148 248 C149 249 C150 250 151 251 0152 252 C153 253 C154 254 0155 2
31. 073 R074 80795076 R07 2078 8079 ROBO 081 R082 R083 80844085 8086 8087 8088 R089 R090091 8092 8093 R094 R095 R096 R097 R038 R099 8100101 81025103 R104 R105 R106 R107 R108 R109 R110 R111 R112 56 Parts No 82300041 05 82300045 63 82300041 05 82300045 63 82300041 04 82300044 74 82300047 53 82300041 04 82300044 74 8230 0044 70 82300046 81 82300041 03 82300041 05 8230 0041 54 8230 0041 03 8230 0041 04 8230 0044 74 82300044 73 82300041 04 82300044 74 82300044 73 82300044 72 82300041 04 82300044 74 82300041 04 82300044 74 82300048 23 82300044 74 82300041 04 82300043 31 82300044 72 82300044 73 82300047 53 82300041 03 82310013 33 82300041 64 82310012 23 82300047 53 82300047 52 82300041 23 82300041 03 82300041 02 82300041 04 82300044 72 82300041 03 8230004472 82300041 03 8230004821 8230 0042 72 8230 0041 04 82300044 74 82300041 03 82300041 04 Nomenclature Vertical mounting iM Deleted Vertical mounting 49 Vertical mounting 1M VR metal flat mtg B Vertical mounting H VR metal flat mtg B Vertical mounting iM 56KQ 56 100 470K 75k 100KQ 470KQ 470 6800 150K2 470 2 47k2 4 4 76 TOOKR 470KQ 470 82 100 3300 4 7 4K 160K 22
32. 2 nr C Parts 8212024200 8260031000 8260030000 8214008000 8249002000 8220031000 8214013000 8204007001 8249 005000 8204 007004 8220031000 8220024000 8220 025000 8214007000 8210 002000 8242 019000 8242 020000 8242 021000 8242 022000 8223 017000 8214 006000 8220 0350 00 8212 029000 8220 0462 00 8214 0111 00 8273 083000 8220 0341 00 8259 003000 8259 004100 8273 029000 8223 016100 8220 033000 8223 015100 8220 054000 8223030000 8212 025100 8260 021000 8223 004100 8212 027000 8260 018000 8223 029000 8212 026100 8223 028000 8216011000 8214 007000 8260 023000 8216 019200 8220 047100 8214 016000 8204 005001 Nomenclature Reel table Brake assembly R 1 Spring Solenoid Bracket solenoid Spring Pin SP3X10 Solenoid Pin SP3X20 Bracket solenoid Lever fast winding Lever brake Spring FF solenoid Housing Transformer power 100 120 220 240 100240 Collar cue Spring Arm cue Knob cue Base head Spring head assembly head terminal Bracket head mount Head 8T o 8T PCB assembly sensor Collar head guide Guide edge head Guide spacer head Chassis assembly sub Cap impedance roller Roller impedance Base assembly impedance roller Cap pinch roller Cover pinch roller Pinch roller Cap tension roller Roller tension Base tension roller Screen tension arm Spring Arm assembly tension L Cush
33. 2 030333 8232 0313 92 8232 031272 Nomenclature Electrolytic 50 luF 20 5M PES 50V 0 0047 5 AMX Electrolytic 16V 10 20 SM PES SOV 0 047uF 5 SM Electrolytic 16V 10 20 SM 50V 0 22uF 20 S 470uF 20 SM PES 50V 0 033uF 5 AMX O luF 5 AMK 0 033uF 5 AMX 5 0 14 5 AMX Electrolytic 16 33uF 20 SM Deleted Electrolytic 16V 20 LR VB Ceramic 504 Q OluF YF Electrolytic 35V 4 7uF 20 SM Ceramic 50V 22 10 SL Electrolytic 35V 4 7uF 20 SM 25 22uF 20 SM 35V 4 7uF 20 SM 25V 10uF 20 SM PES 50 1000 5 AMX Deleted Ceramic 50 100 10 SL Electrolytic 16 100uF 20 SM luF LR BP Ceramic 50V 270 10 YB Electrolytic 16V 33uF 20 SM Deleted PES 50V 0 015uF 5 AMX Ceramic 50V 22pF 10 SL Electrolytic 16V lOuF 20 SM A 507 luF 20 SM Ceramic 50V 47 10 SL PPR 100 0 033uF 2 APS PES 50 4700pF 5 AMX PPR 1007 0 01 2 APS Electrolytic 50V 0 22uF 20 KA 5 16V 33uF 205 SM Deleted Deleted PES 507 3300 54 Elect 25V 4 7uF 20 LR VB Electrolytic lOuF 16V 5 Polypropylene 0 033uF 100V G PPR 1007 3900pF 5 APS 2700pF 63 Ref 148 C149 C150 151 C152 C153 C154 C155 C156 C157 C158 8311 R312 R313 R31
34. 2 8234000203 256181568 R020 82300041 01 1000 Q023 8234000303 254101568 ROZT 82300044 72 4 7K Q024 8234000203 25 181568 R022 82300041 01 1008 0025 Deleted R023 82300044 72 4 70 0026 8234000303 25 101568 R024 82300041 01 1000 0027 8234000203 25C18156R R025 8230004472 4 7 0028 8234000502 258834 R026 82300041 01 9 lo Q029 8234000802 250880 8027 028 82300041 03 x 0030 8234000203 256181568 R029 8230004472 5 4K 4031 8234000802 250880 8030 82300041 03 Q032 8234000203 256181568 R031 8230004472 5 4260 0033 8234000303 254101568 RO32 82300041 03 0034 8234000203 25C18156R R033 8230 0041 04 B 100 0035 Deleted R034 2830 0041 03 0036 8234000303 25 10156 8035 8230 0041 01 1000 0037 8234000203 2SC1815GR 8036 8230 0047 53 0038 82340008 02 250880 8037 8230 0042 22 i 2 20 0039040 82340002 03 250181568 R038 8230 0041 02 Q041 8234000502 2SB834Y R039 8230 004105 i 1m 0042 8234 0002 03 25 181568 8040 8230 0042 22 2 2 Q043 8234 0008 02 2SD880Y R041 8230004102 0044 8234 0002 03 2SC1815GR R042 8230 004105 1 i 1m 0045 8234 0008 02 250880 80434044 8230004563 5 5 55 Ref No R045 8046 047 2048 8049 050 R051 R052 R053 R054 056 R057 R058 R059 R060 R061 062 R063 647 065 066 067 8068 8069 R070v071 072
35. 3 THE CONTROLS AND THEIR FUNCTIONS 1 2 3 4 5 6 7 8 Head shield gate The head shield gate is manually operated If the gate is retracted down a short downward push of rise by spring action locked at the limiting Rewind button REWIND Depressing this button the left reel Fast forward button F Depressing this button right reel Stop button STOP All modes of ZERO RIN tape stopped when this Play button PLAY Depressing this button Record button RECORD its top edge will release its lock and the gate fully To retract it the gate is pressed down and will be position transports tape at high speed from the right reel to FWD transports tape at high speed from the left reel to the REWIND F FWD RECORD and PLAY will be cancelled and button is depressed puts the recorder in the play mode a With more than one and up to four RECORD TRACK buttons depressed simulta neous depressing both RECORD and PLAY buttons puts the tracks thus assigned in the record mode b With more than one and up to four RECORD TRACK buttons depressed and with the transport in the PLAY mode simultaneously depressing both RECORD and PLAY buttons puts those tracks thus assigned to the record mode punch in Return to zero position ZERO Depressing this button puts the transport in the rewind mode automatically rewind tape to 0000 of the tape index counter and then go to the
36. 34001703 82340007 00 CAPACITORS 82320784 78 8232035103 8232077338 8232035103 8232079228 82320351 03 8232 0031 08 PCB rectifier 2W02 02 184002 Electrolytic 4700uF 5 Ceramic 7 1032 Electrolytic 330008 35V 5 Ceramic HE70SJYF103Z Electrolytic 2200uF 639 SMVP Ceramic HE7OSJYF103Z Electrolytic 1000uF 16V SNVP Ref No A F001 A F001 AXFOOI AS F002 A F002 A F002 A F003 A F003 A F003 A F004 A F004 A F004 44250 xc ds nM Parts No Nomenclature MISCELLANEOUS 8239000100 Holder fuse 5 5051 5239000200 x 515053 8239000540 Fuse 4A 250 8239 0003 40 o UL CSA 4A 2507 8239 0007 40 SEMKO 4A 250 82390005 15 o DM 1 54 250 8239000316 Oo UL CSA 1 63 250V 82390007 16 9 SEMKO 1 63 250 8239 0005 20 DM 2A 2504 8239 0003 20 UL CSA 2A 250 8239 0007 20 SEMKO 2A 250 8239001110 DM 1A 250 8239 0006 10 UL CSA 2507 82390007 10 1 250 67 PCB ASSEMBLY HEAD TERMINAL HEAD TERMINAL PCB ASSEMBLY ASS Y No 8273 0830 00 Ref No Parts No Nomenclature 8251121000 PCB head terminal CARBON RESISTORS 80014007 8230034102 Flat mtg 1 6W 1 0 5 CAPACITORS C0014007 8232 026123 PES 50V 0 012uF 5 AMX PCB ASSEMBLY CHANNEL DISPLAY CHANNEL DISPLAY PCB ASSEMBLY ASS Y No 8273012000 Ref No Parts No Nomenclature 82510291 00 PCB chann
37. 4 R315 R316 R317 8318 64 248 249 250 251 252 253 254 255 256 257 258 321 322 323 324 325 326 327 328 Parts No Nomenclature Deleted 8232002107 Electrolytic 10V 1004 20 SM 8232 026183 PES 50V 0 018 5 AMX 8232 005475 Elect 35 4 7uF 20 SM 8232 003106 Electrolytic 16 10uF 20 SM 8232 026104 PES 50V 0 1 5 AMX 8232072475 Electrolytic 4 7uF 25V LRVB 8232027683 PES 50V 0 068 AMX 8232035103 Ceramic 50V 0 010 YF 8232072106 Electrolytic 25V LRVB 100 25V SM 8232 0041 07 g CARBON TRIMMER POTS 8231004103 Vertical mounting 10 2 8231 0045 03 50 2 8231 0045 02 5 SK 82310041 03 y k TOK 8231 0042 02 5 2KQ 8231 0041 03 VOKR Deleted Ref No 102 1103 203 4101 201 Parts Nomenclature MISCELLANEOUS 8248 0060 06 8242 004000 8245 011019 8276 0010 00 8276 002004 8276 001000 Relay sub mini G2E 182P H Coil 0 8mH Cnctr jack 3024 19AH white Pin header x12 Wire jumper 10mm 195 1041 4 x39 Pin header X9 PCB ASSEMBLY FUNCTION COUNTER ASS Y FUNCTION COUNTER ASS Y 8273030004 The following components deleted from the Ass y No 8273030001 Parts List will then be that for the A BLR TRANSISTORS 9001 0009 DIODES 2001 0013 CARBON RESISTORS ROO R025 R040 CAPACITORS Cool 002 PCB ASSEMBLY FUN
38. 5 OP ow 113800 0228 8104 3149 2039111250 0009109629 eu AGZ Ol 243410232913 90 1202629 2203 KDE x 2099000229 a 22400029 1108 100009629 f A001 30062 8 8 44 44 04 161502623 1202 EZ 1700 0428 905 n ME og 00 0128 9108 81009124 105500929 10404 GANS AOS nl 243410432213 0 1900228 0202 a amp 69000428 2219000228 108 900 102600928 9 148 92 6019602628 6102 AL 2 1900 0629 903 z 2000578 108 81 00 gt 052009629 004601 84 665 8102 UNS v EZ22 000 28 OL u 01002 ELO zlOU 10 08009628 eat GANS 191 E 213 90 1020228 1103 OL EL 0 1900 0623 00 2904 OL u 211100 0623 8120912 1711610 1055009629 20040 TEDLSAPSOLIH 24848 EDISEOZEZS 9195102 amp Lv900 0628 Lote 50100128 0107009 SANG ADL POL 21210112213 901020228 s 01000028 21 vico EZ3 160133 50 38 48482 601502228 210 1102 o EY o 21900628 acos p 149 nt 9 1 FOO 0629 1008 4033903 g 4 0009204528 T d 0001108528 11803550 04 08 8012180 51783559 8 xc 52 3542220 ED 29 0914 NO
39. 55 C156 256 C157 257 C158 258 R311 R312 R313 R314 R315 R316 R317 R318 321 322 323 324 325 326 327 328 L103 K101 J101 203 192 201 Parts 8232 0261 53 8232 0265 62 8232 0724 75 82320303 33 8232 0313 92 8232 0312 72 8232 0321 21 8232 0021 07 8232 0261 83 8232 0054 75 8232 0031 06 8232 0261 04 8232 0054 75 8232 0276 83 8232 0351 03 8232 0721 06 8232 0041 07 Nomenclature PES 50V 0 015uF 5 AMX PES 50V S600pF 5 AMX Elect 25V 4 7uF 20 LR VB Deleted Polypropylene 0 033uF 100V G PPR 100 3900pF 5 APS z 2700 Ceramic 120pF 5 NPO Electrolytic 10 100uF 20 SM PES 504 0 018uF 5 AMX Elect 5 4 7uF 20 SM 164 20 SM PES 50V 0 1 5 AMX Elect 35 4 7uF 20 SM PES 50V 0 068uF 5 AMX Ceramic 50V 0 014 YF Elect 25V lOuF 20 LR VB 25V 100uF 20 SM CARBON TRIMMER POTS 8231004103 Vertical mtg lOKGB 8231 0045 03 50Kop 8231 0041 03 8231 0045 02 SKAB 8231 0042 02 2 8231 006473 o metal 47K68 Deleted MISCELLANEOUS 8242 004000 Coil 0 8mH 8248006006 Relay sub mini 62 182 8245 011019 Cnctr jack 3024 19AH white 8276001000 Pin header x12 8276 002004 Wire jumper 10mm IPS 1041 4 x39 The following parts list is for R P AMPLIFIER PCB ASSEMBLY 38cm s Ass y No 8273 0820 00 R123 R151 8152
40. 8 22 8230 0045 62 8230 0041 05 82300042 72 82300042 23 82300045 63 8230 0041 04 82300043 33 82300041 04 8230 0043 61 8230 0043 33 82300041 04 82300042 73 8239 0043 34 Nomenclature TKR 208 22ka 27 8 5 6Kn TMQ Vertical mtg 2 7Kn 56 100K2 33K 100 9 3600 33Ka Tooka 27 330K2 Ref No C101 C102 C103 C104 C16 C106 C107 C108 C109 110 C111 12 C13 0114 C115 116 7 118 C119 C120 C121 C122 0123 C124 C125 C126 C127 C128 C129 C130 131 0132 C133 C134 L135 C136 137 0138 0139 140 141 142 0143 C144 C145 C146 147 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 Parts No CAPACITORS 8232 0061 05 8232 0264 72 8232 0031 06 8232 0264 73 8232 0031 06 8232 0182 24 8232 0024 77 8232 0263 33 8232 0261 04 8232 0263 33 8232 0261 04 8232 0033 36 82320711 06 8232 0351 03 8232 0054 75 82320512 20 8232 0054 75 8232 0042 26 82320054 75 8232 0041 06 82320261 02 8232 0511 01 8232 0031 07 8232 0851 05 8232 0342 71 8232 0033 36 8232 0261 53 82320512 20 82320031 06 8232 0061 05 82320514 70 8232 0303 33 82320264 72 8232 0301 03 82320182 24 8232 0033 36 8232 0263 32 8232 0724 75 8232 0031 06 823
41. 8232 0034 76 8232 0273 33 8232 003476 8232 0273 33 8232 0024 76 8232 0041 07 8232 0271 52 8232 0061 05 8232 0351 03 8232 0021 07 8232 0351 03 8232 0021 07 8232 0351 03 8232 0054 76 8232 0064 74 8232 0021 07 8232 0268 22 8232 0312 22 8232 0054 75 8232 0674 74 8232 0634 76 Nomenclature Ref No Parts No Nomenclature Deleted i MISCELLANEOUS AT J101 8245024002 Connector jack 2P W 5045 02F a E 9102 8245001005 6 M 5045 05 e J103 8245001007 7P W 5045 078 Deleted 3104 8245024022 RE 5045 02F Vertical NOME MM UII d J105 B245001010 5045 10 Delet d 3106 8245001008 W 5045 08A OR 2107 8245024042 2P BL 5045 02F 5 1000 8245001003 3P W 6045 038 4 709 8245000004 W 5045 044 0110 8245001006 6 W 5045 06A am 8245001024 RE 5045 04 Ceramic HE70SJYFI03Z 12 8245024002 5045 028 Electrolytes 70006 3113 8245 001044 4 AP BL 5045 04 teram 8245024022 RE 5045 02F Electrolytic 50V 2 2uF Ceramic 7054 1032 Mylar 0 0047uF 50V Ceramic 7052 1032 Electrolytic luF 50V SMVB Ceramic 7050 1032 Electrolytic lOuF 16V SHBVB 0 47uF 507 5 Ceramic HE70SJYF103Z Electrolytic 2 2uF 50V SHBVB B 4 uF 35V SMVB Mylar 0 0068uF 507 K Deleted Mylar 330pF 100V K Deleted Elect
42. AD Fig 6 12 3 Adjust the Azimuth and Phase Adjusting Screw for maximum reading on all eight VU meters of the recorder Then connect the vertical input of the oscilloscope to TRACK 1 output and the horizontal input to one among TRACKS 2 8 set the oscilloscope to mode to obtain a lissajous waveform to check the phase Trace for vertical input alone Trace for horijontal Unequal levels input alone 80 4 5 If the trace length between 1 2 are not the same it means that the two inputs are not of the same level Correct for equal lengths by the oscilloscope controls If the playback head azimuth is out of alignment the following patterns will result small misalignment 30 A larger error 90 A big one 180 out of phase outof phase out of phase Perfect azimuth 0 in phase Fig 6 13 As a result of phase check with a lOKHz signal the adjustment is finished if difference in phase is less than 90 between tracks and azimuth adjustment is at the best point Check the playback frequency response of each channel by playback of the Frequency Response section of the Reproduce Alignment Tape The recorder VU meters can be used for this check but if a more accurate measurement is necessary the level meter is plugged one by one into the recorder rear panel 1 8 OUTPUT jacks and the levels measured here The normal playback frequency response should be within 3dB for a frequency rang
43. Analog Dolby NE 652 1102 202 8236027700 3 654 1103 203 8236 0210 00 455900 1104 204 8236 0209 00 NUM 4559DF 1105 205 8256 0130 00 Module low pass filter 25KHz U1 06 206 n 0107 207 82560120 00 4 skewing 108 208 8256 0140 00 trap 100KHz 0109 209 8256 0150 00 TRANSISTORS 0101 201 82340001 09 FET 25 117 0102 202 8234 0002 03 25 18156 0103 203 8234 0006 02 25028788 3 0104 204 82340001 11 FET 25 11768 0105 205 8234 0002 03 2SC1815GR 0106 206 1 0107 207 a 0108 208 8234000602 25028788 0109 209 8234 0002 03 2SC1815GR DIODES 0102 106 8234 003500 MA 150 FVS 0201 206 8234003500 150 FVS D108 208 5 0107 207 82340007 00 194002 CARBON RESISTORS All resistors iW 5 unless otherwise R101 201 8230004273 Vertical mtg R102 202 5 8 R103 203 8230023123 7 R104 204 82300237 53 5 R105 250 82300043 34 b 5 R106 206 82300043 94 4 R107 207 82300043 34 5 308 208 8230 0043 94 R109 209 82300041 23 amp 110 210 8230 0048 22 8111 211 8112 212 82300041 04 2 8113 213 8230 0042 01 8314 214 82300041 53 R115 215 8230114154 8116 216 82300045 61 R117 217 82301141 03 8118 218 8230 0045 62 R119 219 8230 0043 33 5 8120 220 82300042 23 F R121 221 82300045 62 7 noted 278 metal 12 1 330 0 390K2
44. CTION COUNTER ASS Y No 8273030001 Ref No 1901 0001594 000204 00055006 0007 010 0011 0001005 0006009 0010012 0013 00141922 0023 ROOT ROQ2 003 2005 2006 ROO Parts No 1 Nomenclature 8251033100 PCB function counter IC s 8236007100 TRANSISTORS 82340002 03 8234 0003 03 82340002 03 8234001003 DIODES 8234 0018 00 8234 0039 00 8234 0018 00 8234 0039 00 8234 DOTS 00 8234 0039 00 Digital LM8523 25 18156 Deleted 2SAT015GR 250181568 256848 150 154WK 150 154WK 150 1548 CARBON RESISTORS 8230006223 Flat mounting iW 8230006334 82300062 23 82300061 04 82300064 74 8230 0061 04 22 3300 22kn 100 4708 100 Ref No R008 009 010073 R014 8015 16920 80214023 80244029 8031 R032 RO33 8034 ROIS 8036 8037 8038 8039 8040 RO41 001 002 0003 005 C006 C007 Parts 82300061 03 82300064 73 82300061 03 82300062 23 8230 0061 02 82300062 23 8230 0346 21 8230 0066 21 8230 0064 72 8230 0061 02 82300061 02 82300061 04 8230006474 8230006103 82300061 02 8230006331 82300064 71 82300064 72 82300061 81 82300064 72 CAPACITORS 82320222 25 8232 035 03 8232 0031 07 8232 0351 03 Nomenclature u 2 Flat mtg 1 64 y o0 VM 47KR 22kQ IKR 22KR 6202 J 6200 4 7Kn
45. H ASSY CONNECTOR BOARD PCB ASSY aN SE C S 1 s 620 2 G 4 1 e E TG lt DISPLAY SWITCH PCB ASSY B DISPLAY LED COM FROM FUNCTION COUNTER Ha assy muat V encoveyoecone HOON RE Ul NEC IND REMOTE Li FROM REMOTE PCB ASSY 70 180 US MCI400 B 01 254101504 U2 MCI407IB 92 2SCI8I5GR MCHMOTIB Q3 250181568 U4 MCI40508 UM MCIAOTIB Qa 2SCiBISGR US MCI40BIB MCI4073B 01011 ANISO 0 22 DIS ANISO RECORD REPRODUCE AMPLIFIER A 8LR yungi 379 7 210 221 19 m 340 NO vi9 270 pe sep At Muirr 8 1 83 58 33 83 Ni 3100 om age 1 2 w TAB VALID g CONNECTOR BOARD A 8LR 5 LON 1600 1 10 02321582 asciowsz 80 OSI vw OSI OW Wocignose 0 1 ASSY 89d OL A r ASSY 82d 08908 MHOJO3NNCO 2124 6 4
46. ODE mode but then 04 10 will go to and thus CHAN 5 qoes to the ENCODE mode 5 ROUTINE MAINTENANCE Troubles and breakdown in the recorder can be prevented by scheduled checking and maintenance Periodically follow the check items listed below a Cleaning the heads and tape guides All heads and guides in the tape path must be cleaned after each 6 hours of operation or before starting a new session of recording Cleaning fluids specially prepared for tape recorders is recommended b Cleaning the pinch roller Clean at least once after each full day of use A cleaning fluid which will not attack rubber must be used 22 Cleaning the capstan g Clean this at the same time the head is cleaned The same cleaning fluid is recommehded Demagnetizing of heads and tape guides After cleaning all heads and tape guides they should be demagnetized every morning or before starting a new session of recording 1 Be sure to switch off the recorder 2 Have all tapes at least 5 or 6 feet away when demagnetizing because the demagnetizer s magnetic field will erase them 3 Slowly wave the tip of the demagnetizer up and down in front of each head then slowly move it away Slow movement is recommended as any abrupt motion can remagnetize the head Like a turtle take your time to repeat the pro cess on the other heads After you finish work on all heads draw the demagnetizer an arms length away
47. OR 652 u 2000028 LEZ LELY o0 5 Boe HUA 366191252 02000 2 602 01D m 2 0 900028 662 8918 UNDE 4 06000028 962 IEL 98181252 209000 9628 802 91d mey 2000628 LSZ ESL tose P 08000628 952 9513 MEZ reli o BE SUNE 902 900 66000828 652 SLY ELWODOTZB EEZ p Lt 85349 EZpPODOEZO 127118 29518152 6020009628 502 9010 2199000628 952 9519 a LECVOOOEZE ZEZ me 91552 133 1110009528 502 FOLD wel 40 524000628 652 44 mU 7 EUNDEM 88182252 2090009528 602 010 5 zsz 2813 NEZ 20028 OEZ OFLU e 38618152 2020000028 202 2010 paqa a0 52 194 m 50001628 622 6213 Bee E ALLENSZ 134 6010009628 102 71010 amp osz 0514 mes 2995000628 822 8214 pac s x 50015154091 223 d 5 4 WSL 002000 690620028 02 HOLY 8 0005109528 602 60Un AS 5 LIMEN HU dq SE x Jimi ge SL EZIEZOOEZB 02 mol 4 dei 0009109528 802 HOLM wide 202 202 2018 Gunes 0002109528 402 coin T S 020006 2195200628 99279003 x k or 10 si 6999000629 592 Sbiu 299000028 EZZ
48. R035 8230 0001 04 100 R036 8230 0004 72 4 7 R037 8230 0001 03 10 8 R038 8230 0001 04 u 5 100KR 8039 8230 0002 43 24 8040 8230 0001 04 1009 RO41 8230 0003 33 5 5 gt 33K R042 8230 0001 4 100 R043 8230 0004 72 2 4 7KQ R044 8230 0041 03 10 0 8045 8230 0041 04 Vertical mounting 100 8 9 046 8230 0002 43 24 8047 8230 0001 04 5 100 8048 8230 0003 33 33KQ R049 8230 0001 04 100 0 2050 8230 0004 72 4 7kQ 8051 8230 0001 03 RO52 8230 0001 04 5 100 8053 8230 0002 43 24 0 1054 8230 0001 04 5 100 055 8230 0003 33 T 33KR R056 8230 0001 04 5 100 0 8057 8230 0004 72 4 4 7 0 8058 8230 0001 03 5 10 R059 8230 0001 04 100Kn 060 8230 0004 72 3 gt 4 7K R061 8230 0004 73 479 8062 8230 0004 72 5 5 4 7KQ 8063 8230 0004 73 8064 8230 0041 64 gt 160K2 R065 B230 0041 63 16 R066 8230 0001 04 LOOKR 2067 8230 0004 74 470K 2068 8230 0001 03 L b 10 8 8069 8230 0006 21 2 6200 R070 8230 0001 81 5 1802 R071 8230 0001 03 5 100 RO72 8230 0001 04 s 100K0 8073 8230 0004 73 47KQ 074 8230 0004 72 4 7 amp 075 8230 0001 04 5 100KR
49. STOP mode Record track selector RECORD TRACK Tracks to be recorded on are selected by combined depressing of the RECORD TRACK and GROUP select 9 buttons This recorder can record on a maximum four channels in one recording pass but the remaining four channels can be recorded by using the GROUP select switch Therefore either tracks 1 or 5 2 or 6 3 or 7 and 4 or 8 are selected by the RECORD TRACK buttons and track groups of 1 2 3 and 4 or tracks 5 6 7 and 8 are selected by the GROUP select button a When the GROUP button and the RECORD TRACK button are assigned the LED s located at upper left hand corner of each meter corresponding to the assign 9 10 11 12 13 ed tracks will blink to indicate that these channels are in the record ready state While in this state simultaneously depressing both RECORD and PLAY buttons put the tracks thus assigned to the record mode and the blinking LED s change to a constant lighting b Should the PLAY and RECORD buttons be depressed at the same time with none of the RECORD TRACK buttons depressed the RECORD LED located at right of the tape index counter 11 will blink to indicate record ready state of the recorder Now if any the RECORD TRACK button is depressed the LED above the VU meter for the assigned channel will light and the RECORD LED also change from blinking to constant lighting Further if all of the RECORD TRACK buttons are rele
50. W European models 240V AC 50Hz 60W UK Australian models 100 120 220 240V AC 60W General export models ia W x 13 1 2 H x 6 3 4 D 29 lbs 13Kg 6 SPECIAL MAINTENANCE 6 4 RECORD REPRODUCE AMPLIFIER CHECKS AND ADJUSTMENTS Checking and adjusting of the record reproduce amplifiers can speedily and efficiently be carried out by following the procedures below Model A 8LR R P amp card installation CH 1 8 2 CH 7 CH 3 CH 6 CH 4 CH 5 PCB Assy Record Reproduce 4 3x6 Plate locking 6 4 1 Calibrating the Dolby encode mode and meters 1 2 3 4 5 6 7 Put transport in the EDIT mode To calibrate TRACK 1 depress the RECORD TRACK 1 button simultaneously depress RECORD and PLAY buttons to put TRACK 1 CHAN 1 in the record mode Plug in an audio oscillator output to the recorder rear panel INPUT 1 jack and apply 400Hz 1048 0 3 signal Set the NR INT EXT switch on the recorder front panel to EXT connect a level meter to test point 101 and adjust REC CAL 311 10KNB so that the level here is 390mV On completing the above adjustments connect the level meter to OUTPUT 1 jack on the recorder rear panel and check that the level here is 104 0 3V 1dB After checking the OUTPUT jack level adjust METER CAL R 312 for a 0 VU reading on the recorder VU meter Calibrate tracks 2 8 in the same way Return the NR INT EXT s
51. WER AC power is applied to the unit and the VU meters lighted when this button is depressed The capstan motor will not rotate unless the takeup reel side tension arm is up or in other words unless the shut off switch linked to the tension arm is on but the capstan motor will rotate even though the tension arm is down only when in the EDIT mode Reel clamper The reel is secured to the reel turntable by CW rotation of this clamper Transport function remote connector REMOTE TRANSPORT Remote operation of the transport function controls is possible by connecting the optional Model 8030 Remote Control Unit Punch In Out remote jack REMOTE PUNCH IN OUT This jack is used for punch in out of the recording by a foot switch Any one button among the four RECORD TRACK selector buttons is depressed and the trans port put in the PLAY mode Then if the foot switch is depressed the previously Selected track goes to the record mode if the foot switch is depressed again the record mode is cancelled and the transport goes to the record ready play mode With none of the RECORD TRACK selector buttons depressed and the recorder in play mode depressing the foot switch will make the record indicating LED to blink indicating that the recorder is in the record ready state while in play mode When any one of the RECORD TRACK selector button is depressed under this condition the track of the depressed button will go to the record mode
52. Y mode and check the meter reading The MONITOR switch must be at TAPE is in normal condition if th meter reading is 0 VU 1 5 VU If it is off spec correct by adjusting REC LVL R315 5KQB Do the same on the remaining tracks 2 8 6 4 8 Overall frequency response 1 2 With the front panel switch at EXT and under the measurement setup of the previous Section 6 4 7 apply signals from 40Hz through 18KHz 15 ips and 40Hz through 15KHz 7 1 2 ips at 1 0 3 to the recorder INPUT jack and set the NR switch to INT To adjust TRACK l for example apply the signal to INPUT 1 and plug in a level meter to OUTPUT jack 1 Put TRACK 1 in the record mode to record a certain length of the signal rewind it to the start and playback the tape It is in good normal condition if the frequency response in reference to 400Hz is within 3dB and 3dB If it does not fall within spec in the high frequency region correct it by a slight rotation of REC EQ pot R316 lK B Check and adjust the remaining tracks in the same way 6 4 9 Overall S N measurement 1 2 3 84 Set the front panel NR INT EXT switch at INT Upon completing checking up to Section 6 4 8 apply 400Hz 10 0 3V sig n l to the rear panel INPUT jack 1 example for track 1 record the signal onto blank tape then without stopping the tape unplug the oscillator connected to the INPUT jack and further record a length of
53. and 041 is switched off by the 1 level from 05 18 in the same way as for PLAY mode and the 24V DC applied to L2 FAST SOL drops to 16V DC C45 is provided to drive the intermittent solenoid when the transport is put in either F FWD or REWIND modes from the PLAY mode When the transport is put in either the F FWD or REWIND mode C45 is charged through D46 or D47 during which Q39 switches on C34 is discharged and when C45 reaches full charge Q39 switches off which in turn charges C34 and the inter mittent solenoid drive circuit is activated as previously mentioned 4 6 REEL MOTOR DRIVE CIRCUIT The left and right reel motor drive circuits are identical except for the additional Q28 and Q29 in the takeup reel motor circuit Q28 and Q29 act to stop the takeup reel motor when the PLAY button is depres sed during the EDIT mode Setting the EDIT switch to IN shorts the emitter of 011 to zero volt and if the PLAY button is now depressed the L level output of U9 17 inverted to H by the inverter switches on 011 Switching on of 011 then switches off both 027 and 028 At this point the 24V DC flows into the base of 029 via R140 D55 and D56 to switch it on This switch on of Q29 results in a short circuit across the motor terminals thus electrically stopping it Except for PLAY mode during EDIT 028 is always in the on state When the PLAY button is depressed in other than the EDIT mode U9 17 goes to L but is inverted and
54. applied to Q21 to switch it on which in turn switches on 16 026 036 Now the takeup reel motor torque is adjusted to 320g cm 50g cm by R129 22 0 and the supply reel motor torque to 220g cm 50g cm by pot R161 22KQ which adjustments result in potentials of 14 5 15V at pin 12 of 012 14 and 13 5 14V at pin 3 of 012 1 012 14 030 031 and 012 1 037 Q38 are constant current output circuits and as the potential across R136 and R167 changes in accordance to the motor current these potentials are fed back to the constant current circuits of U12 14 and U12 1 The two circuits of 012 8 024 and U12 7 Q34 are provided to prevent a sudden high tape tension by gradually raising the voltage to the takeup reel motor at F FWD or REWIND modes Taking for example the circuit of U12 8 and Q24 when power is switched on the potential from the dividing resistors R131 and R132 R136 for 24V DC charges C30 via U12 8 The integration circuits of Q2 C35 and C49 R87 are the boost circuits to prevent tape slacking at start up in the PLAY mode When an level is applied to C49 from UlO 4 an level is applied to Q2 for a certain length of time during which Q2 switches on This in turn applies level to pins 13 and 2 respectively of 012 14 and 012 1 thus raising the amplifier gain at each output which results in increase of motor currents and consequently rise in motor torque Then when Q2 switches off after
55. ased the RECORD LED will change to blinking again to indicate that the recorder have changed from record mode to the record ready state Group select button GROUP Refer to 8 and 10 Monitor select button MONITOR When none of the MONITOR select buttons are depressed the meter indications and the signal output will be for reproduce When any one of the MONITOR button is depressed the input signal will be available at the line output and can be monitored with the VU meter In the same way as for the RECORD TRACK buttons the channel to be monitored must be selected by the MONITOR select button in combination with the GROUP select button Counter display Revolutions of the supply reel table is detected by two photo interrupters and shown on a 4 digit display Reset button The counter display reset button which clears the display to 0000 Edit button EDIT The EDIT switch is provided to facilitate precise splicing of tape after remov ing an unwanted section of tape When this slide switch is set to OUT upper side the transport will be in the normal operating mode and when set to IN lower side it will be in the EDIT mode When in the EDIT mode the transport will not go into any other mode except PLAY and STOP 14 15 16 17 the EDIT mode the shut off switch linked to the right tension arm will ineffective and therefore the capstan motor will rotate upon switching on the power swi
56. ashers and nuts Pan Head Screw Stove Head Screw Truss Binding Head Screw Flat Countersunk Head Screw MACHINE SCREW Orval Countersunk Head Screw Pan Washer Head Screw Round Head Wood Screw Ow Oval Countersunk Wood Screw Qu Pan Head Self Tapping Screw type Pan washer Head PTPWH Self Tapping Screw type Stove Head Self Tapping Screw B type Omm Flat Countersunk Head rmm Sel Tapping Screw 6 type Pan Head Tapping Screw WOOD SCREW T Pan Washer Head Tapping Screw Stove Head Tapping Screw TAPTITE SCREW TAPPING SCREW Flat Countersunk Head Tapping Screw Pan Head Screw with Spring Washer Pan Head Screw with Washer and Spring Washer Flat Washer Spring Washer Internal Teeth Lock Washer WASHER LUG NUT Externa Teeth Lock Washer BOLT serscrew WASHER LUG NUT Trim Washer Countersunk cm Hex Not 620 Thrust Washer Poly Washer FEB 13 Hex Socket Setscrew Flat Point 2 2 5 5 Slotted Socket Setscrew Cup Paint ER Hex Soket Head Bolt Gum ili E Ring 1 Retaining Washer CAR C Ring Inner CRS C Ring Outer RING PIN Zinc pl
57. but 23 24 10 will be cancelled returning to the record ready state when the foot switch is depressed again One word of caution the foot switch can neither punch in nor out when the transport is put in the record mode by the control panel PLAY and RECORD buttons Input output jack INPUT OUTPUT The number of input is four which are routed to the channels 1 4 group or channels 5 8 group by the GROUP select button on the front panel The number of output is eight and an RCA phono jack is provided for each channel Power cord 4 FUNCTION OF THE CONTROL CIRCUITS 4 1 SYSTEM CONTROL CIRCUITS Control signals which are the foundation of tape transport operation are processed by the TTL type LSI U9 In the System Control of this Unit the U9 output pins for PLAY STOP F FWD REWIND REC and BRAKE are used in the various control circuits and when a low level is input to the pin corresponding to the output for that function a low level is obtained at that output pin 4 2 PERIPHERAL CONTROL CIRCUITS OF THE LSI 1 2 3 CR 1 09 5 This is the reset signal input pin of 09 At switch of power 09 5 goes to level for the length of time that Ql is on thus resetting 09 When power is switched on C21 begins to be charged during which time the base of Ql goes to H thus switching on Ql When C21 becomes fully charged the base of Ql goes to L thus switching off 01 When power is
58. cal mounting 1W 15 J 5 6 a 43ka Deleted Vertical mounting 4W 2 7 0 9 Vitreous enamel flat mtg 32 Vertical mounting iW Ka J 4 8 n 56 3 100KQ 5 4700 Vertical mounting 47KQ J 68KQ 4700 x 6 8KQ Deleted Vertical mounting 44 47KQ 82KQ VR carbon flat mtg 22 Vertical mounting 48 15 J 6 8 Deleted Vitreous enamel flat mtg 3W 32 Vertical mounting 44 2 7K2 J a a 1 200 050100 C 09 100 Ref 8179 R180 R181 R182 R183 8184 R185 R186 R187 R188 001 002 C003 C004 005 C006 C007 012 C013 6014 0015 00165017 2018 0019 2020 0021 C022 C023 C024 C025 C026 C027 6028 6029 6030 C031 C032 C033 6034 6035 C036 C037 C038 6039 6040 041 00424043 044 045 C046 6047 C048 C049 6050051 6052 Parts 82300044 73 82300041 03 82300041 04 82300044 73 8230 0046 83 82300041 01 82300044 72 CAPACITORS 82320351 03 82320031 06 8232 0351 03 8232 0062 25 8232 0351 03 8232 0274 72 8232 0351 03 8232 0061 05 8232 0351 03 8232 0641 06 8232 0064 74 8232 0351 03 8232 0672 25 8232 005475 8232 0276 82 8232 0313 31 8232 0654 75 8232 0273 33 8232 0273 32
59. check pinch roller pressure and takeup tension for correct values and see that the tape path is clean 6 4 RECORD REPRODUCE AMPLIFIER CHECKS AND ADJUSTMENTS Checking and adjusting of the record reproduce amplifiers can speedily and efficiently be carried out by following the procedures below Model 8 R P amp card installation CH 1 CH 2 CH 3 CH 4 CH 5 CH 6 7 CH 8 PCB Assy Record Reproduce 3x6 Piate PCB locking 35 6 4 1 Calibrating the Dolby encode mode and meters 1 Put transport in the EDIT mode To calibrate TRACK 1 GROUP select is set to 1 4 depress the 1 5 RECORD TRACK button simultaneously depress RECORD and PLAY buttons to put TRACK 1 CHAN 1 in the record mode 2 Plug in an audio oscillator output to the recorder rear panel INPUT 1 jack and apply 400Hz 1048 0 39 signal 3 Set the NR INT EXT switch on the recorder front panel to EXT connect a level meter to test point TP 101 and adjust REC CAL R 311 10 so that the level here is 390mV 4 On completing the above adjustments connect the level meter to OUTPUT 1 jack on the recorder rear panel and check that the level here 104 0 3V 1 5 After checking the OUTPUT jack level adjust METER CAL R312 50 for a 0 VU reading on the recorder VU meter 6 Calibrate tracks 2 3 and 4 in the same way then switch GROUP select to 5 8 for adjusting tracks 5 v 8 by the same procedures 7 Return the NR
60. cket replace the belt through the cutout at right of the bracket 29 3 3 8 Reel Assy Power Transformer 4 4x8 Reel Assy 3 3x6 NAI 3 3x6 Reel Motor Assy 3 3 6 Capstan Braket Fig 6 7 Assemble in reverse order whereby the belt is inserted through the cutout strung on the flywheel and capstan motor pulley and then the thrust bracket reinstalled 15 Replacing the reel motor drive belt With the top panel removed as in Fig 6 5 hold the brake in their released state and remove the belt through the gap between the brake drum and brake band taking care not to bend the brake band The new belt is reinstalled in reverse order through this gap 6 3 TRANSPORT CHECK AND ADJUSTMENT 1 Pinch roller pressure Pinch roller pressure is supplied by the Pinch Roller Pressure Spring only and it is most important that the solenoid plunger be fully bottomed before taking pressure measurement a Place deck in the EDIT mode Attach a suitable spring scale to the pinch roller shaft with a short loop of twine Put the deck in the PLAY mode and positioning the scale as illustrated slowly draw it in direction opposite the capstan until the pinch roller stops rotating 30 d The spring scale should indicate 4 4 lbs 10 2 0 kg 310 e If the reading is off specification loosen the 2 screws Refer to Fig A and re position the plunger solenoid As
61. cord a length of no signal tape 3 Plug a level meter into OUTPUT jack 1 playback the recorded signal section to measure the noise level of the no signal section against the 400Hz reference level calculate the difference between noise level and reference level add l2dB to it and obtain the ratio between peak recording level and noise level 40 1 2 3 4 Specification 72dB weighted 60dB unweighted 410 T H D measurement Set the front panel NR INT EXT switch to INT To adjust TRACK 1 for example apply a 400Hz 10 0 3V test signal to INPUT jack 1 record it playback the recorded tape and apply its output from OUTPUT jack 1 to the distortion meter Specification T H D 1 or less If it is not within spec demagnetize the head check the bias trap adjustment and record level If it still does not fall within spec after making the corrective measures above readjust the bias current by the procedures in the previous Section 6 4 6 When the Section 6 4 6 adjustments are made it is necessary to go through pro cedures in Sections 6 4 7 and 6 4 8 6 4 11 Erase measurement 1 2 3 4 5 Set the front panel INT EXT switch to To adjust TRACK 1 for example apply lKHz OdBV 1 signal which is 104 higher than the reference level to INPUT jack 1 and put TRACK 1 in the record mode Partially rewind the tape to retain a section of the 1KHz signal and then record over
62. djustments on the record reproduce amplifier is possible without removing the bottom cover as previously mentioned but for adjusting the bias trap coil or to connect AC voltmeter and oscilloscope to the test point at adjusting trim pots the record reproduce PCB must be brought out by using the extension card Fostex P N 8273059000 Upon removing the plate holding down the PCB s by unscrewing the four screws A the record reproduce PCB can be brought out by using the extension card as these are all of the plug in type PCB Assy Record Reproduce 8 4 3x6 Plate PCB locking Fig 6 3 5 Amplifier assembly Fig 6 4 Upon loosening a total of eight screws A four each on both sides on the side chassis of the amplifier assembly it can be pulled out from the housing Sw Suc 4 3x6 27 6 Tape transport mechanism Fig 6 5 Remove five screws A and loosen the two screws securing the solenoid Unhook the spring shown in the drawing Remove the pinch roller rubber after taking off the cap by turning it CCW The base plate with the capstan assembly head assembly roller and tension arm assembly all mounted as a single unit on it can be taken out CAUTION The pinch roller pressure must be adjusted to its correct value whenever this unit is removed and reinstalled Spring 5 3x6 Unhook this spring B Loosen these two screws to allow easy removing of plunger f
63. e Ull 1 output to L which then switches off 019 and the motor is stopped However the motor will continue to run in the EDIT mode even if the shut off switch is on as the EDIT switch is in series with the shut off switch 4 5 INTERMITTENT SOLENOID DRIVE CIRCUIT Two plunger solenoids are used in the tape transport mechanism One is for activating the pinch roller in the play mode and releasing the brake and the other for activating the lifter in the fast forward or rewind modes and also to release the brakes Output pins 17 and 18 of 09 goes to when the PLAY button is depressed The level from pin 17 is inverted to level by 010 4 and applied to 944 to switch on both 044 and 045 On the other hand the L level from pin 18 switches off 039 which then starts to charge C34 161 R172 and R171 This charging of C34 switches on 040 but is switched off after a certain length of time which also switches off 041 Therefore when 045 is switched on the PLAY solenoid Ll is energized by the 24V DC flowing through 041 064 Ll 045 When 041 is switched off the 24 DC drops to 16V DC as the current will now flow through 065 11 and 045 When the F FWD button is depressed output pins 09 22 and U9 18 goes L level and when the REWIND button is depressed pins 09 23 and 09 18 goes to L level The signals from U9 22 and U9 23 are applied to Q42 via the OR gate of D46 and D47 15 On the other h
64. e of 509 18 000Hz 15 ips and 50 15 000Hz 7 1 2 ips If it is not within spec adjust REP EQ R313 1 odd number tracks or R323 lOK B even number tracks Whenever R313 and R323 are adjusted the Dolby encode must be recalibrated Item 5 2 81 6 4 4 Bias leakage check Two bias trap modules are provided for each channel One is in the first stage of the reproduce amplifier and the other in the output stage of the record amplifier 1 Reproduce bias trap module 0109 odd number channels 0209 even number channels To check bias leakage of TRACK 1 the oscilloscope probe is hooked to TP 105 and the probe ground clip to the nearest GND Put TRACK 1 in the reproduce mode the adjacent TRACK 2 in the record mode and check bias leakage at TP 105 If this is less than 250mV P P 15 ips and 700mV 7 1 2 ips it is normal At checking TRACK 2 put the adjacent tracks l or 3 in the record mode If the voltage is high it is adjusted by rotating the center core of 0109 but before doing this check the frequency 100KHz t0 5KHz of the erase bias master oscillator To check the oscillator frequency the record reproduce amplifier PCB is pulled out from the A 8 and the frequency at connector pin No 2 is checked If the oscillator frequency is largely off spec replace the erase bias master oscillator module 013 2 Record bias trap module Ul08 odd number channels U208 even number channels To check bia
65. e tape index counter and then go to the STOP mode Record track selector RECORD TRACK These eight pushbuttons determine whether recording can commence on a given track The specific function also depends on whether or not tape As stopped or is advancing in the record ready mode a If tape is stopped depressing a RECORD TRACK button places the corresponding track in the record mode and the LED above that track s meter 17 will blink If the RECORD button only is depressed the VU meter indi cations and signals from the OUTPUT jacks will change from tape out to input monitor only for those channels whose 73 9 74 RECORD TRACK buttons depressed and the record LED 16 will change to blinking This mode will be cancelled depressing the STOP PLAY or ZERO RTN buttons but will not be cancelled by depressing F FWD or REWIND buttons If the RECORD and PLAY buttons are subsequently depressed tape begins recording the track s meter LED 17 stops blinking and remains on and the record LED 16 also turns Although the VU meter indications and signals from the out put jacks will go to input signal monitor of the channels only which go to record mode by this operation the other channels will remain in the tape out signal monitor mode b If tape is rolling in the PLAY mode depressing a RECORD TRACK button has the same effect as in a above it readies the track for recording In this condition the VU mete
66. el display 8276147000 Cover LED DIODES 00013004 8234 0014 01 Opto LED LN222RP 68 CHANNEL DISPLAY 8251029 00 n DSI 9 O71 5 194 0 SCHEMATICS Remote control TAPE TRANSPORT SYSTEM eios CONTROL PCB ASSY REMOTE CONTROL UNIT L SW PCB ASSY 202 4202 07 1981 FOSTEX CORP 8298 013000 8 69 70 SCHEMATICS Power supply RECTIFIER PCB ASSY 1 4002 2 Ov lav T22V 22 0 22 Ov 22 v 24V UNREGULATED AVCUNREGULATED Ov 4 14 OV 8V sv 0 5 OVi 24v OV 24v REGULATOR ASSY _ 11 1982 FOSTEX CORP 8298 0263 00 A 8 A 8LR Model A 8LR _ Service Manual There are two types in the A 8 LR Series the LOW SPEED 7 1 2 ips version and the HIGH SPEED 15 ips version The majority of adjusting methods for the A 8 LR are identical with the A 8 and the points and methods different from the A 8 only are detailed in the 8 LR SERVICE MANUAL Therefore the A 8 SERVICE MANUAL should referred to for other servicing data 71 20 2 20010 3003 1 75 5401 S dni iun T CONTROL ur k 1 4 MON lt PLAY
67. elapse of a certain length of time C35 starts to charge the voltages applied to pins 13 and 42 respectively of U12 14 and 012 1 gradually rises and each amplifier gain drops to their normal level Then if the F FWD button is depressed the L level from U9 22 is inverted to an H level and applied to the base of Q22 which switches on both Q22 and Q23 At switching on of 023 the 424V DC passing through R116 and R119 further charges C30 and the voltage divided by R116 and R119 is applied to 012 14 As the potential applied to U12 14 rises slowly in step with the charging rate of C30 the motor current also rises cradually resulting in a smooth rise in tor que of the takeup reel When the transport is put in the REWIND mode from F FWD the level from U9 23 is inverted to switch on 032 and Q33 but at the same time switch off 022 and 023 At switch on of 033 the 24V DC flows through R148 and D50 to switch on 024 which quickly discharges C30 down to the emitter potential of Q24 or in other words the output potential of 012 8 C30 is also discharged when the transport is put in the STOP mode from F FWD 17 In this case the L level from 09 19 is inverted to H level applied to 09 and 010 to switch it on thus feeding a base current to 024 through R125 D49 to switch it on thus discharging C30 EDIT 59 17 PLATO 59 12 3 9 22 uF F FOO 222 9 REW O 9 9
68. er Sync crosstalk must be measured of course when the head is replaced with a new one 3 It is in good normal condition if sync crosstalk is 10dB or better when either track of two adjacent ones is put in the record mode 4 To adjust TRACK 1 for example load a blank tape on the transport put TRACK 1 in the sync mode playback and TRACK 2 in the record mode Plug in a level meter to the TRACK 1 OUTPUT jack an audio oscillator to the TRACK 2 INPUT jack and apply a 20Hz 20KHz 108 0 3V signal to the recorder Thus the signal appearing at the TRACK 1 OUTPUT is sync crosstalk If crosstalk from TRACK 1 OUTPUT is higher than 104 0 3V TRACK 1 cannot be playbacked for transferring to TRACK 2 as oscillation will occur 5 As TRACKS 2 through 7 will each have two adjacent tracks either one side only is put in the record mode at taking measurements It could be useful in using this recorder if for reference the figure for both tracks in the record mode is measured 42 ASSEMBLING HARDWARE CODING LIST All screws conform to ISO standards and have crossrecessed heads unless otherwise noted 7 EXPLODED VIEW PCB ASSEMBLIES AND PARTS LIST ISO screws have the head inscribed with a point as in the figure to the right FOR EXAMPLE 6 sess sakhay Length in L Diameter in mm D u atas Metric System Lr Nomenclature Inner dia for w
69. erall frequency response is within 3dB between 250Hz and 10KHz or within 5dB when the higher end is l4KHz During this adjustment temporarily set the screwdriver adjusting slot of REC EQ R316 1 so that this slot is parallel with the PCB plane then trim it for a more flat overall frequency response 6 4 7 Recording level adjustment 1 Proceed to the following adjustments only after checks and adjustments in the previous Sections 6 4 1 6 4 6 have been completed Set the front panel NR INT EXT switch to EXT 2 Load a blank tape Ampex 457 Scotch 227 on the transport and apply an audio oscillator output of 400Hz 10 0 3V to the INPUT jack on the recorder rear panel Also plug in a level meter to the OUTPUT jack Taking TRACK 1 as an example the connector number is 1 for both INPUT and OUTPUT jacks 3 Depress the RECORD TRACK 1 button then depress the RECORD and PLAY buttons to put TRACK 1 in the record mode When thus in the record mode the meter will indicate the input level regardless to select position of the input button Check to see that the reading of this meter is 0 VU 321 VU 4 It will be convenient to rewind the tape to the start if the tape index counter reset button is depressed at start of recording to return the display to 0000 5 After recording a certain length of 400Hz VU signal depress the ZERO RTN 83 button to rewind tape to the starting point put the transport in the PLA
70. eting Colored zinc plating Black zinc plating Nickel plating Black plating Chrome plating BCr Black chrome piating 43 Ref Parts No 1 8212 040100 2 82600360 00 3 8223 0290 00 4 8212 0260 00 5 8223 0280 00 6 8223 0040 00 7 8212027000 8 8260018000 9 8260039000 10 8226017000 n 8226 0120 00 12 82260150 00 13 8270049000 14 8226 0090 00 15 8226 0060 00 16 8214 0030 00 y 8270119000 18 8273 082002 19 8220 044100 20 8212 033000 21 8216 0030 00 22 82200520 00 23 8207 0006 00 24 8226 0130 00 25 8226 0210 00 Nomenclature Housing head Panel trim transport Cap tension roller Roller tension Base tension roller Cap pinch roller Cover pinch roller Pinch roller Panel 55 trim amplifier 8T Button reset Button push Button control Transport assembly 8T Knob slide Knob 11 Washer R P amplifier assembly 8T assembly R P amplifier Plate PCB locking Cover bottom Foot Plate cover Plastic rivet No 794 Button push B Reel clamper The following apply to A 8LR only 9 8260 096000 Panel ass y trim amplifier 8T 18 8273 082001 ass y R P 19 5 8273 082002 o 707 38cm s 44 RALL R P AMPLIFIER 31545 7 081809 1 431545 18 4455 95 Ref m Q m
71. etween 250Hz and lOKHz or within 5dB when the higher end is l4KHz During this adjustment temporarily set the screwdriver adjusting slot of REC EQ R316 1 so that this slot is parallel with the PCB plane then trim it for a more flat overall frequency response 6 4 7 Recording level adjustment 1 Proceed to the following adjustments only after checks and adjustments in the previous Sections 6 4 1 6 4 6 have been completed Set the front panel NR INT EXT switch to EXT 2 Load blank tape Ampex 457 or Scotch 227 on the transport and apply an audio oscillator output of 400Hz lOdBV 0 3V to the INPUT jack on the recorder rear panel Also plug in a level meter to the OUTPUT jack Taking TRACK 1 as an example the connector number is 1 for both INPUT and OUTPUT jacks 39 3 Set the GROUP select switch to 1 4 and depress 1 5 of the RECORD TRACK button Depress the RECORD and PLAY buttons to put TRACK 1 in the record mode When thus in the record mode the meter will indicate the input level regardless to select position of the input button Check to see that the reading of this meter is 0 VU 1 VU 4 It will be convenient to rewind the tape to the start if the tape index counter reset button is depressed at start of recording to return the display to 0000 5 After recording a certain length of 400 2 VU signal depress the ZERO button to rewind tape to the starting point put the transport in the PLAY mode and
72. ignal at the input Rewind to start of recording playback the tape insert a 1KHz bandpass filter between OUTPUT 1 and the level meter to measure the output The level ratio between the 1KHz recording and the no signal recording is the erasure figure It is in good normal condition if erasure is higher than 70dB If it is less than the spec increase erase current about 10 by the procedure of Section 6 4 5 Monitor the erase current waveform on the oscilloscope at adjusting and set the core just before the waveform begins to deteriorate A higher current will heat the erase head and result in damage to the tape 6 4 12 Sync crosstalk measurement 1 Sync crosstalk is the relative figure against the reference level on how much of the recording signal from the track in the recording mode is leaking into the track being reproduced When sync crosstalk is excessively high playback output during overdubbing will 85 2 3 4 5 86 sound muddy by effect of the recording signal leakage or cause oscillation at ping pong recording whereby the playback output is transferred to another track Sync crosstalk occurs in relation to the track and pitch dimensions of the head and its construction and since this cannot be corrected without affecting its frequency response to be aware of how much margin there is before oscillation occurs at ping pong recording is very important at drawing out best performance from the recorder Sync cross
73. ile it is in steady motion and multiply this value by the hub radius to obtain the torque Be sure the twine is not rubbing against the reel flange when taking meas urements The specified torque is 7 8 in oz 220 g cm 20 If adjustment is required adjust 8161 22 pot as required Takeup tension adjustment procedures 1 2 Place an empty 7 reel with a spring scale attached to the hub by a length of twine on the right reel table Place deck in the PLAY mode 33 3 Allow the reel to slowly wind in the scale 4 Follow the spring scale travel with enough force to allow a steady reading and multiply this value by the reel hub radius to calculate the torque 5 The specified torque is 11 2 in oz 320 g cm 20 6 If adjustment is required adjust R129 22 pot as required Tension increase R1 Take up tension adj 29 R161 Back tension adj U PCB Assy System Contro REAR VIEW Fig 6 11 4 Wow and flutter Wow and flutter measurements should be undertaken only after studying the follow ing items and determining which method and standard will be employed a Determine whether the Reproduce Method or the Record Reproduce Method is to 34 employed for measurement If the Reproduce Method is to be employed a flutter test tape will be re quired Recommended test tape Fostex P N 8266008000 Standard Tape Lab 53 1 or equivalent In the Reco
74. ion felt Locking spring Spring Screw Sholdek Ref No Parts Mo Nomenclature 48 8260022000 Arm assembly tension R 49 8220041000 Arm joint 50 8214014000 Link 51 8214007000 Spring 52 8260024000 Lifter assembly A 53 8216007000 Tube 54 8214009000 Spring 55 8260026000 Plate assembly shield 56 8220042000 Plate shield 57 8212030100 Knob shield 58 8214010100 Spring shield plate 59 8260015000 Shaft assembly 60 8210001000 Flywheel 51 8223007000 Shaft pinch roller solenoid 62 8260019000 Arm assembly pinch roller 63 8214031000 Spring 64 8214012000 Spring 65 8260034200 Chassis assembly 66 8216005100 Belt reel 67 8253016000 Switch micro 68 8220030000 Bracket safety switch 69 8249004000 Motor capstan 70 8220023000 Bracket motor 71 8216008000 Bushing 72 8204006001 Screw Sholdek 73 8223008100 Pulley capstan 74 8216006100 Belt capstan 75 8249003000 Motor ree 76 8223009000 Puley reel 77 8276007000 Harness assembly ree motor 78 8276030000 79 8220026000 Bracket capstan 80 8216010000 Sheet 81 8270032001 Rectifier assembly DM 8270032002 5 USA 8270032003 5 E EUR 82 C203 8232035103 Cap ceramic 0 014 50V 0204 83 201 u C202 ty 0205 E a 84 8216041000 Stopper 49 Ref t m m 10 11 12 13 14 15 16 17 18 A 19 P P gt P P P 20 21 22 23 24
75. ment procedures given this manual which also includes Parts List and schematic diagrams to assist the service technician in maintaining the Model A 8 Please feel free to contact the nearest Fostex Dealer and Distributor or write directly to a Fostex office the addresses of which are printed on the back cover of this manual Noise Reduction System manufactured under license from Dolby Laboratories Licensing Corporation Dolby and the double D symbol are trademarks of Dolby Laboratories Licensing Corporation CAUTION A Parts marked with this sign are safety critical components They must always be replaced with identical components Refer to the Fostex Parts List and ensure exact replacement 1 INTRODUCTION Fostex Model A 8 is a small size lightweight 8 track 8 channel recorder reproducer for 1 4 tape It features simple switching between sync and record modes by combined action of the RECORD TRACK and MONITOR selectors and simple switching of the monitor to these modes punch in out without any clicks in the recording zero position return function of the tape counter the rewind mode pitch control function and other features necessary in multi track recording In addition approximately 20dB of noise reduction is obtained by the built in Dolby C Type noise reduction system Other types of noise reduction system can also be used with this recorder by the front panel Noise Reduction Switch which all
76. ne or more RECORD TRACK buttons are depressed Record LED Located above each VU meter These LED s will blink or glow continuously depending on what combination and sequence the RECORD TRACK buttons and the transport control RECORD button is depressed If any RECORD TRACK button is depressed after the transport control RECORD and PLAY buttons are depressed in the PLAY mode and record ready state the LED of the channel corresponding to the depressed button will glow continuously With none of the four RECORD TRACK buttons depressed and while the transport is in the play mode record ready state all four LED s of channels 1 4 or 18 19 20 21 22 channels 5 8 selected by the GROUP select button will blink under this condition if any one or up to four of the RECORD TRACK buttons correspond ing to the channels of the blinking LED s are depressed the LED of the de pressed channel only will glow continuously and the other LED s will be ex tinguished If any RECORD TRACK button is depressed during ZERO RTN REWIND F FWD PLAY or STOP modes the LED of the depressed channel will blink Cue lever CUE The lifter mechanism lifts the tape away from the head in the ZERO REWIND and F FWD modes The cue lever is provided to allow tape cueing when the tape is thus lifted from the head Shifting the cue lever moves the lifter pins toward the head and the tape will touch the head Power switch PO
77. no signal tape Plug a level meter into OUTPUT jack 1 playback the recorded signal section to measure the noise level of the no signal section against the 400Hz reference level calculate the difference between noise level and reference level add l2dB to it and obtain the ratio between peak recording level and noise level Specification 72dB weighted 60dB unweighted 6 4 10 T H D measurement 1 2 3 4 Set the front panel INT EXT switch to INT To adjust TRACK 1 for example dpply 400Hz lOdBV 0 3V test signal to INPUT jack 1 record it playback the recorded tape and apply its output from OUTPUT jack 1 to the distortion meter Specification T H D 1 or less If it is not within spec demagnetize the head check the bias trap adjustment and record level If it still does not fall within spec after making the corrective measures above readjust the bias current by the procedures in the previous Section 6 4 6 When the Section 6 4 6 adjustments are made it is necessary to go through pro cedures in Sections 6 4 7 and 6 4 8 6 4 1 Erase measurement 1 2 3 4 5 Set the front panel NR INT EXT switch to INT To adjust TRACK l for example apply 1KHz OdBV 1V signal which is 10 higher than the reference level to INPUT jack 1 and put TRACK 1 in the record mode Partially rewind the tape to retain a section of the 1KHz signal and then record over the remaining section without any s
78. oes to the down count mode COUNT PULSE Thecount pulse is obtained from Q6 on the System Control PCB The DIRECT count pulse is about 4Hz at beginning of tape wind and about 8Hz near end of tape wind Input pin for selecting the operating mode of the predivider in the stage prior to the lowest digit of the counter to 1 5 or 1 1 As the 1 5 mode is used in this system this pin is open or at L 19 4 RESET The counter and display are reset to all zero by an H level to this AC IN The AC power line frequency 50 60 2 is applied here for the reference frequency OUT 1 At the instant the counter register changes from 0001 to 0000 this driver output pin goes to for a duration of 200 400msec SIX DECADE 1 or open pin to this pin sets the counter to decimal count ing or an H to modulo six of digit two This pin is kept at L or at open in this System SEG la 4g The LED segments are directly driven by these pins 9 RECORD TRACK SELECT LED display circuit The LED corresponding to each track of the RECORD TRACK select buttons either blink or light continuously to indicate the mode of operation 1 2 3 Blinkinq at depressing the RECORD TRACK button The output of multi vibrator 01 and Q2 are applied to Q3 which switches on off Q3 Q4 and Q5 at about lHz 2Hz The output of Q5 is connected to the LED anodes via the GROUP select switch and the cathode of the
79. ot switch 08 is a reset circuit and when the play mode is cancelled an level is applied to pin R of U6 and the flip flop is reset Also when the GROUP select switch is manipulated an L reset pulse is applied to 03 13 and the resulting level from 08 11 applied to the R pin resets 06 DM wo LI X 20211 y 1 22201 L _ 2 10 0 Fig 4 3 13 The signals from 06 1 Q output 09 14 REC 0 output passing through the OR gate of D41 and D40 is applied to the base of Q8 to switch it on if either of the above signals are of H level ahd thus an L level representing the trans port record signal is applied to the RECORD TRACK selector circuit 4 4 CAPSTAN MOTOR DRIVE CIRCUITS If the recorder is switched on with the tape loaded with the left right ten sion arm in the up position the capstan motor begins to rotate at 1 000 rpm and when put in the play mode accelerates to 2 000 rpm 018 is in the on state when power is switched on and this raises the DC level of 011 1 which then switches on 019 to start the motor The 1 200Hz output from the TACH generator applied to Ull 14 is amplified and a square wave is output from its pin 14 This square wave is differentiated by C25 R90 R91 and the plus side of this waveform switches on Ql6 When the recorder is switched on 08 1 goes to 1 014 and 015 switches on and this output is applied to
80. ould be within 3dB for a frequency range of 50 18 000Hz If it is not within spec adjust REP EQ R313 1 odd number tracks or R323 10 even number tracks Whenever R313 and R323 are adjusted the Dolby encode must be recalibrated Item 5 2 6 4 4 Bias leakage check Two bias trap modules are provided for each channel One is in the first stage of the reproduce amplifier and the other in the output stage of the record amplifier 1 2 Reproduce bias trap module 0109 odd number channels 0209 even number channeis To check bias leakage of TRACK 1 the oscilloscope probe is hooked to TP 105 and the probe ground clip to the nearest GND Put TRACK 1 in the reproduce mode the adjacent TRACK 2 in the record mode and check bias leakage at 105 If this is less than 250 it is normal At checking TRACK 2 put the adjacent tracks 1 or 3 in the record mode If the voltage is high it is adjusted by rotating the center core of 0109 but before doing this check the frequency 100KHz 0 5KHz of the erase bias master oscillator To check the oscillator frequency the record reproduce amplifier PCB is pulled out from the 8 and the frequency at connector pin No 2 is checked If the oscillator frequency is largely off spec replace the erase bias master oscillator module 013 Record bias trap module 0108 odd number channels U208 even number channels To check bias leakage of TRACK 1
81. ows patching in of external NR systems to jacks provided for this purpose Maintenance of the transport is made by removing the front trim panel and for checking and adjusting the record reproduce amplifier by removing the bottom cover 2 SPECIFICATION TAPE FORMAT REEL SIZE TAPE SPEED PITCH CONTROL LINE INPUT X4 LINE OUTPUT X8 RECORD LEVEL CALIBRATION EQUALIZATION WOW amp FLUTTER STARTING TIME FAST WIND TIME OVERALL FREQUENCY RESPONSE SIGNAL TO NOISE RATIO THD ERASURE POWER REQUIREMENTS DIMENSIONS WEIGHT 1 4 inch tape width 1 mil base 8 track 8 channel 4 channel X 2 Record 8 channel Reproduce 7 inch 15 ips 38cm s 0 5 10 10 0 39 impedance 15 unbalanced 10dBV 0 39 load impedance 10K or higher unbalanced VU referenced to 250nWb m of tape flux TEC 35 microsecs 0 06 ANSI weighted measured with flutter tape Less than 0 5 sec 130 second for 1800 ft of tape 40Hz 18KHz 3dB 72GB weighted 6048 unweighted referenced to 3 TH D level 10dB above 0 VU at 1kHz Less than 1 at 1 2 0 VU Better than 70dB at 1 KHz 120V 60Hz 60W U S A Canada models 220V AC 50Hz 60W European models 240V 50Hz 60W UK Australian models 100 120 220 240 14 W X 13 1 2 H X 6 3 4 D 29 lbs 13 kg W General export models
82. r indications and signals from the output jacks will be tape out signal monitor for all channels c If tape is rolling in the record ready mode i e RECORD and PLAY buttons have been depressed the record LED 16 adjacent to the tape counter will blink and the LED s above each of the eight VU meters will not blink Subsequent depression of a RECORD TRACK button immediately causes that track to enter record mode the record LED 16 now remains on so does the LED associated with the track s VU meter 17 INPUT MONITOR SELECTOR When this button is depressed signals at the line output jacks and the VU meter readings will be input monitor for all 8 channels This means that while input monitor signals will be output from each channel output jacks whose number corres pond with each channel input jacks at the rear panel at the same time these levels will be indicated by each channel VU meter When this button is in the up position any channel can be monitored by a combination of the desired RECORD TRACK SELECTOR number and the RECORD PLAY buttons on the transport control For instance depress RECORD TRACK SELECTOR buttons 2 and 3 while in the STOP mode then depressing the RECORD button only puts channels 2 and 3 in the input monitor mode and the remain 10 11 12 13 14 ing channels yill be for tape monitor From this condition depressing the PLAY button only can cels the input monitor mode for channels 2 and 3
83. rd Reproduce Method a 3KHz sine wave is recorded on a blank tape rewound to beginning of the recording and reproduced again for the measure ment process NOTE When reproducing the recorded signal at measurements by the Record Reproduce Method adopt the maximum wow and flutter value obtained by repeated play and stop modes of operation which is necessary to be sure that wow and flutter content between record and reproduce will not be in phase to create a false reading Determine the Standard to be used The wow and flutter meter is set to measure the IEC ANSI peak value The wow and flutter meter must be calibrated for weighted measurements a As the measured results will vary with respect to location on tape at which it was taken at least two parts at beginning and near the end of tape should be selected for measurement NOTE Recommended Wow amp Flutter Meter Meguro Denpa Sokki Co Model MK 668C Japan There will be slight differences in absolute value between other manufacturers IEC ANSI peak value Reproduce method 0 06 Record Reproduce Method 0 08 5 Tape speed Tape speed is measured by using the Flutter Test Tape which contains a highly accurate continuous 3KHz tone Connect a digital frequency counter to either OUTPUT The indicated frequency should be 3KHz 0 5 for all speeds If tape speed is greatly offset from the specification
84. rolytic 4 7uF 25V SHBVB Mylar 0 033uF 50V K 0 0033uF 50V K Electrolytic 47uF 16V EUVB Mylar 0 033uF 50V K Electrolytic 47uF 16V EUVB Mylar 0 033uF 50V Electrolytic 47uF 107 SMVB 100uF 25V SMVB Mylar 1500pF 50V K Electrolytic luF 50V SMVB Ceramic HE70SJYF103Z Electrolytic 100uF SMVB Ceramic 052 1032 Electrolytic 100uF 107 5 Ceramic HE70SJYF103Z Electrolytic 47uF 35V SMVB 0 47uF SOV 100 107 5 Polypropylene 0 0082uF 50V J Polypropylene 0 0022uF 100 J Electrolytic 4 7uF 35V SMVB 0 47uF 50V SHBVB 47uf 10V 4115 8245 024042 8220028000 Heat sink 2P BL 5045 02F 57 PCB ASSEMBLY CONTROL SWITCH PCB ASSEMBLY DISPLAY PCB ASSEMBLY CONTROL SWITCH ASSEMBLY No 82730321 00 PCB ASSEMBLY DISPLAY ASSEMBLY No 8273031000 Ref No Parts No Nomenclature Ref No Parts Nomenclature 8251035000 PCB control switch 82510341 00 PCB display 5001006 825 3004000 Switch Tact KHG10901 DIODES 00014004 8234002300 LED display MAN74A 0005 8234001501 LED opto LN233RP S001 8253004000 Switch Tact 610901 58 000088 ehe 16043450438 OLOT 90071009 m u 501500028 90 a a 1001005028 sor gt 4 0629 9604 5
85. rom the solenoid Fig 6 5 7 System control PCB assembly Fig 6 6 Upon removing the two screws A the system control PCB assembly can be swung down pivoted on the lower two screws B The assembly can be taken out completely if either one of the B screw is removed 8 Rectifier assembly Fig 6 5 The rectifier assembly can be removed by unscrewing the two C screws 9 Regulator assembly Fig 6 6 The regulator assembly can be removed by unscrewing the three D scxews 28 10 11 12 13 14 PCB Assy Rectifier 2 3x6 PCB Assy Regulator 222 3x6 2 3x6 PCB Assy System Control 2 4x8 Fig 6 6 Power transformer Fig 6 7 Remove the four A screws Unsolder the primary wires at the power switch and the secondary wires at the rectifier PCB assembly Reel assembly Fig 6 7 Remove the three screws and the reel assembly can be taken out from the front side of the recorder Reel motor assembly Fig 6 7 Remove the three screws C and the reel motor assembly can be taken out The motor lead wires are unsoldered at the terminating PCB Capstan motor assembly Fig 6 7 Remove the three D screws and the capstan motor assembly can be taken out Unsolder the motor lead wires at the terminating PCB Replacing the capstan belt Remove the four E screws shown in Fig 6 7 and after removing the capstan shaft thrust bra
86. s condi tion the transport goes to the stop mode At this point if tape slack is taken up so that the right tension arm is up and then the PLAY button is depressed the transport goes to normal play mode NR INT EXT switch The internal Dolby noise reduction system will be in operation when this NR switch is set to INT 75 15 16 17 18 76 When any other type of system is to be used with this recorder set the NR switch to EXT and connect the encoder to INPUT and the decoder to OUTPUT of the RCA phono jack the rear panel Pitch control knob PITCH CONT The 12 o clock click action stop of this knob is the normal speed 15 ips position and speed can be varied 10 at CCW rotation and 10 at CW rotation respectively of this knob Record LED RECORD This LED will either blink or glow continuously under the following conditions when the RECORD and PLAY buttons are depressed at the same time Will blink if none of the four RECORD TRACK buttons are depressed Will glow continuously if one or more RECORD TRACK buttons are depressed Record LED Located above each VU meter These LED s will blink or glow continuously depending on what combination and sequence the RECORD TRACK buttons and the transport control RECORD button is depressed If any RECORD TRACK button is depressed after the transport control RECORD and PLAY buttons are depressed in the PLAY mode and record ready state
87. s leakage of TRACK 1 the oscilloscope probe is hooked to TP 104 and the probe ground clip to GND nearest to 105 Put TRACK 1 in the record mode and check bias leakage at TP 104 It is normal if the voltage is 1 1 P P If it is off spec check frequency 100KHz 0 5KHz of the bias erase master oscillator before rotating the center core of 0108 to adjust bias leakage 6 4 5 Erase current adjustment In adjusting the erase current put the track to be adjusted in the record mode adjust TRACK 1 for example hook the hot side of the oscilloscope probe to TP 103 located near relay K 101 and the ground clip of the probe to GND pin in front of the REP EQ pot R313 Set the core of L 103 so that voltage at TP 103 is 1 7V P P 15 ips and 1 5V P P 7 1 2 ips 82 The test point for TRACK 2 is TP 203 located near relay L 201 The GND pin to be used is located left of the REP CAL pot R324 erase current is adjusted by the core of L 203 2 6 4 6 Bias current adjustment The track of which bias current is to be adjusted is put in the record mode To adjust TRACK 1 for example hook the osciiloscope probe hot side to TP 102 located near connector J 101 and the ground clip to the GND pin Then set the BIAS LVL pot R317 47KQB at approximately 450mV P P For an accurate adjustment load blank tape Ampex 457 Scotch 227 on the recorder record a test signal set the NR switch to INT and trim the BIAS LVL pot so that the ov
88. stantly when the RECORD and PLAY buttons are simultaneously depressed 1 Blinking By switch on of Q6 by the L level transport record signal an H level is applied to the base of 08 to switch it on but as the emitter of 08 is connected to the collector of 04 via DS 08 will switch on and off in step with 04 and the LED thus blinks 2 Constant lighting When any one of the RECORD TRACK button is depressed under the above 1 state the emitter of 07 is connected to zero volt by the selected button which switches it on and the LED is lighted in the constant state 4 11 RECORD TRACK SELECT Record reproduce amplifier control circuit 06 11 is an exclusive OR gate Each time the GROUP select switch is manipula ted the output of 06 11 goes to to switch on Q3 and pulse is applied to the System Control LSI Due to this the record mode is cancelled by switching of the GROUP selector even if the LSI is in the record mode An encode decode switching record relay control and bias on off control sig nals are sent to the Record Reproduce Amplifier from the RECORD TRACK select cir cuit As the circuits of track 1 through 8 are all identical track 1 only will be taken as an example When GROUP 1 4 is selected input 06 9 is set to and the output 06 10 goes to 1 level if UG 9 is then 06 10 goes to H When inputs U7 8 and U7 9 are at L output U7 10 goes to L or in other words when the RECORD TRACK 1 button
89. switch it off and unplug the cord Testing the brakes See Item 6 3 b Brake torque page 32 Testing the pinch roller pressure See Item 6 3 a Pinch roller pressure page 31 Testing the amplifier Thread a blank tape on the Model 8 and record a 1KHz 0 VU signal While the machine is in the record mode check to see that the meters read 0 VU of first the channels 1 4 group then the channels 5 group by selecting with the GROUP button If adjusting is required refer to Item 6 4 Rewind the above recording to the beginning reset the RECORD TRACK to SAFE and put the machine in the PLAY mode The VU meters should all read VU Record a 45Hz through 18 KHz signal and check the overall frequency response with the VU meter to see that it is within 134 Disconnect any equipment plugged into the INPUT record a length of no signal tape and reproduce it to check the S N ratio In the same way as before re cording and checking is done first on the 1 4 channel group then switched to the 5 8 channel group by the GROUP button and the same steps repeated 23 6 SPECIAL MAINTENANCE 6 1 TEST EQUIPMENT REQUIRED 24 Spring scale Flutter meter Audio oscillator Frequency counter Band pass filter AC voltmeter Oscilloscope Test tapes Blank tape or or or 0 8 lbs 0 4 kg 10 ozs 0 300 gm Meguro Denpa Sokki Model MK 668B Mincom Division 3M Co
90. switched off C21 is quickly discharged through D38 and thus be comes ready for the next switch on of power EBR IN U9 4 In this system brake is applied electrically from REWIND or F FWD before final ly going into the STOP mode For example if the STOP button is depressed during REWIND the transport tem porarily goes into F FWD mode and then into STOP mode when an L level is ap plied to this EBR IN For timing of L level application to EBR IN refer to Tape Counter Detecting Circuit and Motion Sensing Circuit Item 4 7 EDIT The L level signal from the EDIT switch when it is set to IN is not only ap plied to 011 which is the circuit to stop the takeup reel right side motor Refer to Item 4 6 but also to the exclusive OR gate U2 2 When the EDIT switch is set from OUT to IN an L level is applied to U2 2 and as 02 13 is also at L output 02 11 goes to L and as this is applied to U9 6 U9 goes to the STOP mode In the meantime the input to U2 12 will go to H level after a certain delay introduced by the integration circuit of R12 and C3 and output pin U2 11 goes to H level One L level pulse is output from U2 11 when the EDIT switch is set from IN to OUT 11 4 Under H level state of U2 2 U2 13 will also be at level and consequently U2 3 goes to L level After a certain delay U2 12 goes to L level and thus U2 11 goes to H level ZERO RETURN The system goes to REWIND mode when the ZERO
91. talk must be measured of course when the head is replaced with a new one It is in good normal condition if sync crosstalk is 1088 or better when either track of two adjacent ones is put in the record mode To adjust TRACK 1 for example load a blank tape on the transport put TRACK 1 in the sync mode playback and TRACK 2 in the record mode Plug in a level meter to the TRACK 1 OUTPUT jack an audio oscillator to the TRACK 2 INPUT jack and apply 20Hz 20KHz lOdBV 0 3 signal to the recorder Thus the signal appearing at the TRACK 1 OUTPUT is sync crosstalk If crosstalk from TRACK 1 OUTPUT is higher than 104 0 3V TRACK 1 cannot be playbacked for transferring to TRACK 2 as oscillation will occur As TRACKS 2 through 7 will each have two adjacent tracks either one side only is put in the record mode at taking measurements It could be useful in using this recorder if for reference the figure for both tracks in the record mode is measured 7 PCB ASSEMBLIES AND PARTS LIST CONNECTOR BOARD PCB ASSEMBLY Ass y No 8273087000 8TLR Ref No Parts No Nomenclature 8251101100 connector board 1075 0014003 8236 0033 01 Digital MC14071B 4004 8236 0029 01 5 MC14050B 11005 8236 0040 01 408 0006 007 8236003500 0 140738 1008 8236 0001 01 o 140018 0009 4011 8236 0033 01 MC14071B 1012 8236 0029 01 140508 1013 8236 0040 01 4 MC 4081B 0014 8236 0035 00 14073 0015 8256
92. tch and the takeup reel remain stationary when the PLAY button is de pressed In this case the mechanical brakes will be released but no power is applied to the takeup reel motor and the takeup reel can be rotated easily by hand 1f EDIT is switched ON duxing the PLAY mode tape will stop but if the PLAY button is depressed again the tape will be transported at the play speed but will not be wound by the takeup reel If EDIT is switched OUT under this condi tion the transport goes to the stop mode At this point if tape slack is taken up so that the right tension arm is up and then the PLAY button is depressed the transport goes to normal play mode NR INT EXT switch NR The internal Dolby noise reduction system will be in operation when this NR Switch is set to INT When any other type of NR system is to be used with this recorder set the NR switch to EXT and connect the encoder to INPUT and the decoder to OUTPUT of the RCA phono jack on the rear panel Pitch control knob PITCH CONT The 12 o clock click action stop of this knob is the normal speed 15 ips position and speed can be varied 10 at CCW rotation and 10 at CW rotation respectively of this knob Record LED RECORD This LED will either blink or glow continuously under the following conditions when the RECORD and PLAY buttons are depressed at the same time Will blink if none of the four RECORD TRACK buttons are depressed Will glow continuously if o
93. the integration Circuit of R92 R93 and 47 48 Therefore a sawtooth waveform made by the signal from the integration circuit and on off action of 016 is applied to comparator Ull 8 The rectified output from the integration circuit of R98 R99 and C27 passes through 018 and DC amplifier 011 1 and applied to Q19 which controls the current to the capstan motor To PITCH QOWTROL Te SHUT OFF SWITCH 14 020 switches on when 019 is off to act as braking circuit by absorbing the counter electromotive force from the motor When the PLAY button is depressed the 1 output from 09 17 is passed through an inverter and applied to 08 5 on the other hand as the signal to 08 6 is also H the output of U8 4 is an L but on being inverted by 08 10 the H level output is applied to 012 Q12 and Q13 is then switched on and its output applied to the integration cir cuit of R94 R95 and C47 C48 At the same time the output of 08 10 makes the output of U8 3 go to thus switching off 015 By this alternating switching of 913 and 015 the integration circuit constant is affected and output duty of comparator 011 8 is changed As a result the motor revolution changes from 1 000 rpm to 2 000 rpm and consequently the TACH output of 1 200Hz rises to 2 400Hz The TACH output at 1 000 rpm is about 350nV Wnen the shut off switch is on left right tension arm in down position 017 is switched on to force th
94. the remaining section without any signal at the input Rewind to start of recording playback the tape insert lKHz bandpass filter between OUTPUT 1 and the level meter to measure the output The level ratio between the l1KHz recording and the no signal recording is the erasure figure It is in good normal condition if erasure is higher than 70dB If it is less than the spec increase erase current about 10 by the procedure of Section 6 4 5 Monitor the erase current waveform on the oscilloscope at adjusting and set the core just before the waveform begins to deteriorate A higher current will heat the erase head and result in damage to the tape 6 4 12 Sync crosstalk measurement 1 Sync crosstalk is the relative figure against the reference level on how much of the recording signal from the track in the recording mode is leaking into the track being reproduced When sync crosstalk is excessively high playback output during overdubbing will 4l sound muddy by effect of the recording signal leakage or cause oscillation at ping pong recording whereby the playback output is transferred to another track 2 Sync crosstalk occurs in relation to the track and pitch dimensions of the head and its construction and since this cannot be corrected without affecting its frequency response to be aware of how much margin there is before oscillation occurs at ping pong recording is very important at drawing out best performance from the record
95. tons depressed depressing the RECORD button only or both the RECORD and PLAY buttons at the same time makes the tape out signal change to input monitor signal 77 25 26 27 28 29 Power cord Capstan and Pinch roller Supply idler roller Tension arm VU meter 2 SPECIFICATION 78 TAPE FORMAT REEL SIZE TAPE SPEED PITCH CONTROL LINE INPUT LINE OUTPUT RECORD LEVEL CALIBRATION EQUALIZATION amp FLUTTER STARTING TIME FAST WIND TIME FREQUENCY RESPONSE SIGNAL TO NOISE RATIO T H D ERASURE POWER REQUIREMENTS DIMENSIONS overall WEIGHT 1 4 inch tape width 1 mil base 8 track 8 channel 8 channel record 8 channel reproduce 7 inch 15 or 7 1 2 ips 38 or 19 cm s 0 5 10 l10dBV 0 3 Impedance 30 unbalanced 10dBV 0 3V Load impedance 10 or higher unbalanced 0 VU referenced to 250 nWb m of tape flux 35 usecs at 15 ips 50 5 at 7 1 2 ips 0 06 peak IEC ANSI weighted for 15 ips 0 10 peak IEC ANSI weighted for 7 1 2 ips measured with flutter test tape Less than 0 5 sec 130 seconds for 1800 ft of tape 40Hz 18KHz for 15 ips 3dB 4082 15 2 for 7 1 2 ips 3dB 7 weighted 6088 unweighted for 15 ips 72dB weighted 60dB unweighted for 7 1 2 ips referenced to 3 T H D level 12dB above VU at 1 KHz Less than 1 at 1 KHz 0 VU Better than 70dB at 1 KHz 120V AC 60Hz 60W U S A Canada models 220V AC 50 2 60
96. ttom side and a total of six screws B from both sides The four screws A are of the self tapping type 6 4x10 4 PTPWH 4x10 Fig 6 1 2 Tape transport panel Fig 6 2 With the bottom cover removed unscrew the four truss head 4 X 10 self tapping Screws A from the bottom side Next from the top panel side remove the head housing pinch roller and the left and right roller guides The head housing can be removed by loosening the two 3 X 8 hex socket screws B 25 3 4 26 The rubber roller of the pinch roller be removed by taking off the cap with a CCW rotation After removing the left and right rollers by taking off the caps by CCW rota tion dismount the tension roller base by loosening the 3 X 4 set screws C With these components dismounted the tape transport panel can be removed thus permitting adjustments on pinch roller pressure brake torque and tape tension 4 4x10 gt 9 2 HSB 3x8 Fig 6 2 Amplifier panel Meter and control panel Fig 6 2 With the bottom cover removed as in previous item 1 remove two upper and lower screws on the panel side from among the six D screws on both sides of the amplifier section Then draw out the panel section and remove the dress panel by unscrewing the Six screws E from the underside of the panel Record reproduce PCB Fig 6 3 Regular a
97. witch on the recorder front panel to INT 6 4 2 Calibrating the Dolby decode mode 1 2 3 4 Set the NR INT EXT switch on the recorder front panel to EXT and switch off all RECORD TRACK buttons Playback the Reference Level Section of the Reproduce Alignment Tape Beginning adjustments from TRACK 1 CHAN 1 connect a level meter to test point TP 101 located near U106 upon the CHAN 1 PCB of the record reproduce amplifier and adjust REP CAL R314 10 so that the level is 390mV After these adjustments connect the level meter to the recorder rear panel OUTPUT 1 jack and check that the level 10dBV 0 3V 79 5 After check of the OUTPUT jack level confirm that the meter reading is 0 1 VU the reading is not O VU l1VU repeat the adjustments in the previous section Item 5 6 Calibrate tracks 2 8 CHAN 2 8 by the same procedures for TRACK 1 above 7 On completing the above adjustments return to INT the NR INT EXT switch the recorder front panel 6 4 3 Adjusting the reproduce frequency response 1 Set the NR INT EXT switch on the recorder front panel to EXT and switch off all RECORD TRACK buttons 2 Playback the Head Azimuth and Frequency Response sections of the Reproduce Align ment Tape The Azimuth and Phase Adjusting Screw is adjusted for this alignment as shown in Fig 6 12 Height Adjusting Screws Ajimuth and Phase Adjusting Screw ERASE HEAD REC REP HE

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