TI-101 Manual 03-04.pmd
Contents
1. 101 Telephone Interface Manual Radio Systems Inc TI 101 Manual Contents 1 INTRODUCTION i 4 1 1 2 Wire to 4 Wire Conversion sense 4 12 Level hatusta 4 1 2 Dynamic Range Control an nie 4 1 4 Equalization Of RECEIVE Signal u nen 4 1 5 RECEIVE MULE nee 4 1 6 Da 4 2 FUNCTION DESCRIPTION issisicrcsoiosoinonicncacc naninniacanacasionas 5 2 1 Hybrid 2 to 4 wire conversion ri 5 2 2 send Equalization nen 5 2 3 send 5 2 4 Receive Compression Expansion 5 2 5 Receive Equalization au 5 2 6 Telephone Line Interface Cru ae 6 2 7 Receive Output made 6 3 TI 101 BLOCK DIAGRAM 7 4 CONNECTIONS TO THE TI 101 8 4 1 Caller ON PU 8 4 2 MUTE asia 8 4 3 Caller Output Level Swicch eisen 8 4 4 Conterence IN OU aia 8 4 5 NEUE 8 4 6 Input Level 8 4 7 Telephone TIPRING sense 9 5 INSTALLATION sass asss uE 10 6 FRONT PANEL SETUP OF TI 101 11 6 1 11 6 2 Send Level Adjust Host 11 6 3 Receive 4 11 6 4 Hybrid Null Adj st nein 11 62. woo Orient nu overly 950 5 erirmi 912 10 re orn h xot 2 274 A 4610 ns aw 21 Ex kak mios 4 5 Y E D wae ns acer ow OOB8ETKT en 098 L rr Page 16 3 04 Manual 101 Inc SCHEMATICS CONT Systems Radio Have ODINY BALADA 56151 EILITRE Se BAY ML PE ser ses OMI XIMLDMAR rikt AD erteni iro NI 50 wor a z Lo l rr 1170 NMOS ANC ZINFURANDOO NOILWOLSIO NO ze gt ser Page 17 3 04 PARTS LAYOUT 3 04 Page 18 Radio Systems Inc TI 101 Manual PARTS LIST decadas whe DESC ir Be us ANA QTY UM TI 101 PCB DETAIL 9882 1 EA 10 28 29 39 46 001 UF CDISK 100V 1103 6 EA 51 12 50 52 470PF DISK 9913 3 13 14 10PF CDISK 5862 2 EA cis CAP 022UF FILM 100V 10 9322 1 EA C16 CAP FILM 056 UF 50V 8920 1 EA C17 CAP 0022UF 50V FILM 5863 1 EA 18 001UF FILM 5 50 5861 1 19 0068UF FILM 9915 1 3 20 47 DISC 10 500 5742 2 EA C21 C44 CAP 150PF DISK 9910 2 EA C22 C23 C25 CAP 4 70 35V NP 9
3. conference feature of the TI 101 is to be used These are to be provided through the CONFERENCE IN and CONFERENCE OUT jacks on the back of the TI 101 Also the input signal should be line level nominally 10 or 8 dBm depending on the setting of the rear panel LEVEL switch What should do if I still get feedback or too much of the local talent send input signal from my monitor speakers after I null the 101 This can be caused by several conditions 1 Atelephone mouthpiece connected to the line in the same acoustic space as the monitors In general all signals feeding the telephone line must go through the TI 101 2 Thenull adjustment being incorrect This can be because a The telephone line has been disconnected b The 101 is no longer connected to the line for which it was nulled i e it s been connected to a line with different impedance 3 04 Page 24 Radio Systems Inc TI 101 Manual In general anything has been changed about the telephone connection that would effect its impedance 3 The gain from the microphone to the monitor speaker through the 101 is too high Reasons for this include a Too high send or receive levels in the TI 101 or too high receive EQ settings b Too much EQ or too high level settings anywhere else in the mic to monitor signal chain Omni directional microphones microphones or monitor speaker with peaks in their frequency response No
4. panel when the CLIP LED is on 2 4 RECEIVE COMPRESSION EXPANSION The caller signal input will trigger either the EXPANDER or the COMPRESSOR of this circuit depending on which side of the user set threshold the caller level falls on The VCA which accomplishes this operates at zero gain with no signal present When the signal goes above the first threshold the gain increases and when the signal goes above a higher threshold still the gain decreases In this fashion background noise and other spurious low level signals are passed at a lower level than the desired signal and loud signals are somewhat attenuated 2 5 RECEIVE EQUALIZATION Athree pole 18 dB per octave 300 3 kHz bandpass filter attenuates out of band signals and improvesthe quality of the null Gyrator circuits provide symmetrical boost and cut of 8 dB at 400 Hz and 2 5 kHz with a Q at full cut or boost of 9 3 04 Page 6 Radio Systems Inc 2 6 TELEPHONE LINE INTERFACE CIRCUIT The telephone line is buffered by a transformer with good common mode rejection another FCC requirement and high DC breakdown voltage In addition this circuit includes a Metal Oxide Varistor to shunt AC or DC voltages of over 130 volts and a 2 2 uF 250V blocking capacitor to keep DC voltages off the transformer Although the TI 101 is not type approved by the FCC for direct connection to the telephone line itis completely protected should this occur TI 101 Manual 2 7 RECEIV
5. 5 Se al LINIEN eran 11 6 6 Compress Expand Threshold seen 12 6 7 12 7 USING THE CONFERENCE MODI 13 8 SERVICE INFORMATION SCHEMATICS 14 8 1 In Warranty ReBairs a 14 8 2 ULF Warranty RepallS acaso 14 8 3 Schematic DIagrams is 14 3 04 Page 3 Radio Systems Inc TI 101 Manual ls nee 15 Schematics 16 Pars Layout 17 Faris 18 Parts dai is 19 9 101 SPECIFICATIONS 20 10 THEORY OF OPERATIOLN 21 10 1 Deriving a Mix Minus Signal ee 21 10 2 Why Have a Mix Minus Signal u a ke 21 10 3 Using a Small Add on Mixer a aa 21 10 4 Using the Cue Bus of an Existing Mixing Console 22 11 COMMON QUESTIONS AND ANSWERS 23 3 04 Page 4 Radio 1 1 1 1 2 1 3 1 4 1 5 1 6 Systems Inc TI 101 Manual INTRODUCTION The TI 101 telephone interface is intended to allow convenient easy connection of audio equipment to telephone lines by fulfilling the following functions 2 WIRE TO 4 WIRE CONVERSION Most telephone systems are 2 wire bi directional systems That is to say both parties ina conversation are carried on the same pair of wires For
6. R26 R32 RES 560 OHM 1 4W 5 9895 2 EA R2 R8 R9 RES 1 MEG 1 4W 5 1047 3 EA 3 04 Page 19 Radio Systems Inc TI 101 Manual PARTS LIST CONT REG SIRS e DESEA SKU LAP PART QTY UM R30 RES 30K 1 4W 5 3907 1 EA R33 RES 820K 1 4W 5 9908 1 EA R34 R111 RES 10 OHM 1 4W 5 1019 2 EA R36 R49 R105 RES 12K 1 4W 5 9897 3 EA R37 RES 18K 1 4W 5 9898 1 EA R38 RES 24K 1 4W 5 9899 1 EA R39 R40 RES 30 1K 1 4W 1 9573 2 EA R3 R28 RES 510 OHM 1 4W 5 9894 2 EA R41 R42 RES 10K 1 4W 1 2816 2 EA R46 RES 240K 1 4W 5 9906 1 EA R48 R51 RES 110K 1 4W 5 9902 2 EA R4 R35 R56 R57 R82 R RES 1 4W 1 5872 6 EA 108 RS3 R61 R75 RES 39K 1 4W 5 1053 3 EA RS5 RES 470 OHM 1 4W 5 1030 1 EA R59 RES 91K 1 4W 5 9901 1 EA 5 60 RES 180K 1 4W 5 9905 2 R62 R99 RES 270K 1 4W 5 2738 2 EA R63 R109 R110 RES 20K 1 4W 5 1031 3 EA R64 RES 750K 1 4W 1 9057 1 EA R65 R78 R79 RES 15K 1 4W 5 8288 3 EA R67 RES 1 1K 1 4W 1 9625 1 EA 68 69 RES 27K 1 4W 5 8799 2 EA R6 R10 R52 R74 RES 100K 1 4W 1 5876 4 EA R7O RES 160K 1 4W 5 9904 1 R76 R81 RES 51K 1 4W 1 9164 2 EA R7 R31 R47 R50 R102 RES 220K 1 4W 5 2755 6 EA R106 R80 RES 470K 1 4W 5 1122 1 EA R86 RES 1 3K 1 4W 1 9565 1 EA R87 RES 2 2K 1 4W 5 1016 1 EA R88 R89 R107 RES 13K 1 4W 5 8912 3 EA R93 R94 RES 5 6K 1 4W 5 1117 2 BA R95 RES 300K 1 4W 5 8909 1 EA R96 RES 51 OHM 1 4W 5 5728 1 EA R97 R98 RES 18 OHM 1 4W 5 9893 2 EA REF U1 U2 U3 U4 U5 U SOCKET
7. doing this two problems of considerable importance can easily be avoided The first is feedback This situation is very much like speaking into a microphone directly in front of the monitoring speaker Without using a mix minus approach the caller source signal would almost inevitably form a regenerative audio loop resulting in a howl The second problem is echo in the circumstance that the call is satellite delivered This is due to a delay which is inherent to the use of a satellite link in communications Without a mix minus the caller will hear a slap back repeat of his her own voice The following examples provide some of the interfacing methods for a variety of system configurations to derive and apply a mix minus signal 10 3 USING A SMALL ADD ON MIXER Any small mixer with mic inputs can be used to derive a mix minus signal The outboard mixer can be used as a sub mixer for all the mics in the booth If the mixing console used with the 101 doesn t have multiple bus capability this technique must be used if programming is to include guests and therefore the need for more than one studio mic All microphones used during a phone show are routed through the small mixer Since the output from this mixer contains only signals from the studio mics and no caller audio it is by definition a mix minus signal This output is fed to the TI 101 host audio input and to a line input of the air console The TI 101 s receive audio outp
8. most professional and industrial audio applications it is more desirable to have the parties on two pairs so that one can adjust their level independently avoid feedback due to multiple signal paths and perform other signal processing functions LEVEL CONTROL Send host level and return caller level are independently adjustable DYNAMIC RANGE CONTROL The user may adjust a limiter on the send circuit and a compressor expander to reduce telephone line noise on the receive circuit EQUALIZATION OF RECEIVE SIGNAL A boost or cut of 8 dB at 400 Hz and 2 5 Hz may be added to the caller s signal to increase intelligibility RECEIVE MUTE The caller signal may be attenuated by a rear panel accessible contact closure This is especially helpful for repressing the off hook dial tone and dialing generated noises CONFERENCE LINK Two TI 101 s may be connected to separate telephone lines and then interconnected and patched to the user s mixer for three way conversations 3 04 Page 5 Radio Systems Inc TI 101 Manual 2 FUNCTION DESCRIPTION 2 1 HYBRID 2 TO 4 WIRE CONVERSION Hybrids are necessary to separate the host from the caller line so that individual signal routing and processing may be applied to each one To doso the phone line that has a bi directional two wire conversation between the caller and the host must have the host audio removed This can effectively be done by taking the host audio at the source on its
9. own two wire path and adding it to the bi direction conversation audio path with the two host lines in opposite phase Of course the situation is really not quite this simple The telephone line represents a complex impedance network 1 6 not just resistive but capacitive and inductive as well which phase shifts the send signal compared to the original Phase correction must be applied to the send signal in order for it to be subtracted nulled The course null adjusts the hybrid for the variable resistive component of the telephone line the low frequency LF and high frequency HF nulls adjust the phase correction network for the complex components of the line 2 2 SEND EQUALIZATION The FCC requires 18 dB of attenuation at 4 kHz and increasing attenuation at higher frequencies to avoid interference with telephone company equipment This is accomplished by an elliptical low pass filter with a 3 kHz 3 dB point 2 3 SEND LIMITING The send signal is limited by two different methods The first isa voltage controlled amplifier with user adjustable threshold allowing less audible compression of the send dynamic range for greater intelligibility The limit operation is indicated with the enabling of the LIMIT LED on the TI 101 front panel The second method available is hard limiting clipping with a fixed threshold of offering complete overdrive prevention of the phone line and hybrid circuit Operation is indicated on the front
10. with high 4 or 8 dBm output bus levels 3 04 Page 9 Radio Systems Inc TI 101 Manual 4 7 TELEPHONE TIP RING Connections are made from the TI 101 to your phone line on this terminal strip through an FCC approved coupler QKT or other supplied by your telephone company As mentioned above the TI 101 is both transformer isolated and capacitively coupled to the phone line Therefore although and RING are indicated these connections may be reversed without any repercussions 3 04 Page 10 Radio Systems Inc 5 TI 101 Manual INSTALLATION Connectingthe TI 101 in parallel with the host phone line as described below isthe least complex method to interface into your studio system Follow these steps to complete basic installation Splitthe host phone line in a Y with a user supplied RJ 11 splitter This modular phone jack splitter is available through Radio Shack Part 279 357 One side of the split will go to the studio phone The second side of the split will terminate at the terminal connector on the rear panel of the 101 Connection may be made using Radio Shack RJ 11 12 foot extension with RJ 11 and spade lug ends 279 364 Connect the GREEN and RED wires to the terminal connector A PROGRAM INPUT channel from the mixing console should connect to the OUTPUT XLR connector on the TI 101 rear panel The INPUT XLR connector on the TI 101 should receive HOST MIC audio by tapping off o
11. 00 Hz to 3k Hz 3 dB measured from telephone port to output port 20 dB over the specified frequency band width 3 pin XLR type for input and output ports barrier terminal strip for telephone tip and ring 1 4 phone jacks for external mute and conference interconnect cables 1 3 4 high 19 wide 6 deep 4 45 x 48 3 x 15 2 cm 5 lbs 11 0 kg 60 Hz 120 VAC standard 50 Hz 220 VAC upon request All plated steel chassis 3 04 Page 21 Radio Systems Inc TI 101 Manual 10 THEORY OF OPERATION 10 1 DERIVING A MIX MINUS SIGNAL Mix minus refers to one of two almost identical bus mixes The first bus mix which can be thought of as the main mix contains all line inputs as its summed output If a second bus mix contains all but one of the main mix inputs and is identical to it in every other respect it is known as a mix minus In broadcasting situations the mix minus signal usually contains all butthe receive audio the caller This might consist of a host and a guest along with a tape deck ortwo in a studio and a guest calling in on the phone In the studio they are both hearing full audio mix but the caller who is also on the air is hearing a mix which contains all but his own voice 10 2 WHY HAVE A MIX MINUS SIGNAL Utilizing a mix minus as a monitoring send for the remote location allows the remote source to hear all aspects of the mix without sending the source s output back down the line to itself By
12. 8 PIN DIP 1011 8 EA 6 08 09 REF U7 SOCKET 16 PIN DIP 1039 1 EA SW1 SW2 SW3 SWITCH SINGLE STATION 9542 3 EA TRANSFORMER TELEPHONE 9925 1 EA T2 TRANSFORMER T 34X 2842 1 EA 010 17815 3680 1 011 79 15 9920 1 Ul U2 U3 U4 U5 U6 U8 5532 1010 109 U7 IC LM13600 9927 1 EA VR10 VR11 POT 50K CNTR DETENT W HDWRE 9887 2 EA VR1 VR2 VR6 POT 50K PNL MT W HARDWARE 9885 3 EA VR3 POT 100 OHM VERT 9889 1 VR4 VRS POT 50K VERT 9890 2 VR7 POT 500K PLN MT W HARDWARE 9888 1 EA VR8 VR9 POT 1K TRIMMER 9892 2 EA 3 04 Page 20 Radio 9 Systems Inc TI 101 Manual TI 101 SPECIFICATIONS Input impedance Output Impedance Telephone Port Impedance Nominal Input and Output Level Ranges CMRR Maximum Input Level Maximum Output Level Typical THD Controls Visual Indicators Frequency response Typical Transhybrid loss Connectors Physical Size Shipping Weight Power Requirements Construction 16 7K ohms Electronically balanced gt 600 ohms Transformer Balanced 560 ohms Transformer Isolated Switchable between 10 dBm and 8 dBm gt 4 dB at Input 1 kHz 21dBm 20dBm 1 Send Level send limit receive level receive compress expand 400 Hz and 2 5 Hz Equalization conference link coarse low frequency and high frequency null adjust LED s for indication of send clip send limit receive clip receive compress expand receive mute and power on 3
13. 917 3 EA C24 0015UF 50 FILM 9083 1 EA C27 CAP 047 UF 50V FILM 8837 1 EA C2 C4 C9 C40 C41 C43 CAP 1UF CDISK 9045 6 EA C30 C31 C53 00470 FILM 7587 3 EA C32 C33 C42 C58 CAP 1UF TANTALUM 16V 9359 4 EA C34 CAP 220PF DISK 9911 1 EA C36 C54 C55 CAP 01 UF 50V DISC 2741 3 EA C3 C47 C56 C57 CAP 4 7 UF 50V ELEC 8868 4 EA C45 015UF FILM 9558 1 EA C48 C49 CAP 470UF 35V AXIAL 9914 2 EA 5 35 82PF DISK 9909 2 EA C6 CAP 2 2 UF 250V MYLAR AXIAL 9918 1 EA C7 CAP 330PF DISK 9912 1 EA 8 CAP 47UF TANTALUM 9916 1 EA CJ2 CONNECTOR NC3FDH B FEMALE 8402 1 EA CJ3 CJ4 CJ5 1 4 IN JACK PCB MT 9884 3 EA CJ6 CONNECTOR NC3MDH B MALE 8401 1 EA D11 D19 LED GREEN 3MM 9924 2 EA D12 D20 D25 LED RED 3MM 9922 3 EA D1 D2 D3 D6 D7 D8 D9 DIODE 1N4148 1012 17 EA D10 D13 D14 D15 D1 6 D17 D18 D22 D23 D 24 D21 LED YELLOW 3MM 9923 1 EA D26 D27 D28 D29 DIODE 1N4004 1020 4 EA 71 4057 RES 0 0 OHM 1 4 W 7133 57 EA J7 HEADER 3 PIN 156 9883 1 EA MOV1 SURGE ABSORBER 9921 1 EA 01 05 06 TRANSISTOR 254403 6119 3 02 03 04 07 TRANSISTOR 2N4401 6118 4 EA R103 R104 RES 120K 1 4W 5 9903 2 EA R11 RES 1 2K 1 4W 5 5724 1 EA R12 R16 R21 R24 R25 RES 10K 1 4W 5 1017 11 EA R66 R77 R83 R90 R10 0 R101 R13 RES 68K 1 4W 5 1123 1 EA R14 R15 R17 RES 1 5K 1 4W 5 2760 3 EA R18 R19 R91 R92 RES 4 7K 1 4W 5 1121 4 EA R1 RS4 R71 R72 R73 R RES 5 1K 1 4W 5 9896 6 EA 84 R20 R45 R58 RES 82K 1 4W 5 9900 3 EA R22 R23 R43 R44 R85 RES 510K 1 4W 5 9907 5 EA
14. E OUTPUT CIRCUIT This consists of a current boost amplifier emitter follower and transformer for DC isolation and common mode rejection 3 04 Page 7 Manual TI 101 Systems Inc Radio 101 BLOCK DIAGRAM INdino 5341199 E 5 010HS33H1 3211 03 Y3T1V9 3A13938 2 00 ONVAX3 SSIUIMOD 53172 3 303 o 3ISYYOD Or o AYIIMOAIO 13497 Y31149 3A13938 A A x dil 51 3 3 13 dno F 13131 ON3S NI 32 3833 02 O ino ANH JONIYIANOS JINIYIINOO A JIOSNOD OTOHSIYHL ON3S 1 4 N O O 13A31 40 INdNI ex Page 8 3 04 Radio Systems Inc TI 101 Manual 4 CONNECTIONS TO THE TI 101 4 1 CALLER OUTPUT The caller OUTPUT XLR connector feeds the caller s signal to your mixer Pin 3 is high pin 2 is low and pin 1 is ground For unbalanced operation pin 2 may be grounded 4 2 MUTE A user supplied contact closure may be connected to this 1 4 jack When contact is made from ring to tip the caller s signal will be attenuated by a minimum of 20 cB 4 3 CALLER OUTPUT LEVEL SWITCH This switch sets the nominal output gain of the TI 101 Push the switch in for 8 dBm nominal and release the switch for 10 dBm nominal The switch setting is of course dependent upon the requirements of the equipment being interfaced to the TI 101 In particular profess
15. Pack all items carefully and ship pre paid via UPS insured to Radio Systems 601 Heron Drive Logan Township NJ 08085 Attn R A Enclose a note which includes your name company phone number the serial number return address no box numbers and a complete description of the problem 8 2 OUT OF WARRANTY REPAIRS We ll gladly service any Radio Systems product at any time If the warranty period is passed you ll be billed for all necessary parts labor packaging materials as well as any applicable freight charges Remember you must call for an R A number before you send the unit to Radio Systems 8 3 SCHEMATIC DIAGRAMS The schematic diagrams are to be used by qualified service technicians only No license to use this information for anything other than normal repairs is implied to given by the inclusion of proprietary information in the schematic diagrams 3 04 Page 15 Manual 1 101 Systems Inc Radio SCHEMATICS ATAN Whe OOINY LINK 3504 11 JIAVHRHDE erat or sr Atar BAY Hire ther 4 UMOJ gt 20 vA 291 Id ony 8 100021 ime 11 vir an 009 009 52 szo 160181 N a aan sorrne 21 NIYO inert w nce 55 sj ru soo
16. RENCE 2 CALLERS SIMULTANEOUSLY CALLER 2 AUDIO TO CALLER 1 AND CONSOLE CALLER 1 AUDIO TO CALLER 2 DO NOT CONNECT A HYBRID 1 MIX MINUS OUTPUT AUDIO WITHOUT EITHER CALLER CONSOLE NOTES WIRE CONSOLE MIX MINUS TO INPUTS OF BOTH 10175 IN PARALLEL MIX MINUS MUST NOT CONTAIN EITHER CALLER CONNECT BOTH CONFERENCE LINK LINES AS SHOWN CONFERENCE LINK BUTTONS ON BOTH 101 FRONT PANELS MUST BE DEPRESSED BOTH CALLERS MAY BE NULLED SEPARATELY DO NOT CONNECT OUTPUT OF SECOND 101 3 04 Page 14 Radio Systems Inc TI 101 Manual 8 SERVICE INFORMATION SCHEMATICS Radio Systems will service any of its products no matter when it was manufactured or what condition it s in However no goods will be accepted without a Return Authorization Number If we don t know its coming we won t be prepared to make the necessary repairs Before sending anything to Radio Systems call for an number Just ask we ll gladly give you one Call 856 467 8000 weekdays 8 30 a m to 6 00 p m EST 8 1 IN WARRANTY REPAIRS The TI 101 Telephone interface is covered by a limited warranty for a period of one year from the date of purchase The Limited Warranty statement supplied with your unit spells out all the legal details and the generalities that follow are not intended to modify that warranty statement Contact Radio Systems at 856 467 8000 for a return authorization number
17. f the mic input channel at a pre fader point or by using a dedicated mix minus bus from the console A remote contact closure connects to the MUTE jack on the rear panel PHONE LINE 3 04 Page 11 Radio Systems Inc TI 101 Manual 6 FRONT PANEL SETUP OF THE 101 Once the TI 101 has been installed the front panel controls may be adjusted using the following steps 6 1 FOR STARTERS First rotate both equalization controls to their 12 o clock position Then rotate the send limiter threshold control and the receive compressor expander threshold control to their full clockwise position Doing so will effectively cancel these functions for the moment Next rotate the receive level control to its full counterclockwise off position 6 2 SEND LEVEL ADJUST HOST Now call an assistant on the telephone Make sure that your telephone mouthpiece is now either disconnected unscrewed or removed from the acoustic environment in which your microphone is located Speak into your microphone and make the proper level adjustments on your console or mixer Then while speaking into the microphone at a normal voice level advance the TI 101 ssend LEVEL control until the clip LED only occasionally flashes This will give you the maximum send level to the phone line Check with your assistant at the other end of the line and verify that you are being heard clearly and ata proper level 6 3 RECEIVE LEVEL CALLER Adjust your c
18. ional mixing consoles will want to see 8 levels and semi pro gear will want to see 10 levels 4 4 CONFERENCE IN AND OUT These connect to their opposite designated references on another TI 101 that is to say IN to OUT and OUT to IN The conference function is activated by the front panel CONFERENCE LINK switch Refer to Section 7 for details 4 5 INPUT FROM CONSOLE The INPUT XLR connector accepts the send signal the host from your mixing console This is the signal that will be sent to the caller on the other end of the phone line Pin 3 is high pin 2 is low and pin 1 is ground For unbalanced input signals you should connect pin 2 to ground and apply the signal to pin 3 NOTE This signal should be only the talent s voice and not a full mix that includes the caller s signal referred to as a MIX MINUS If you loop the caller s voice back down the line you will cause an echo or perhaps an oscillation Therefore this input to the TI 101 should be fed from the mic pre amp output patch or a separate console bus containing just the talent voice 4 6 INPUT LEVEL SWITCH The output level from your console or mixer can be matched to the input stage of the TI 101 with this switch Press the switch in to the 10 dBm position if your mixer output level is nominally low as the case with a semi pro type of mixer Alternately use the 8 dBm positioning of the switch for professional mixers
19. ly a substitute for the coil in the telephone set must be provided This can be a holding coil such as the following Radio Systems Part No 10170 Triad Utrad Part No TY 350P These are available from many electronic distributors In a pinch one side of a signal transformer either primary or secondary with the other side unterminated can be used It should be approximately 1 2 Henries inductance 180 Ohms DC resistance Also a holding coil salvaged from an old telephone set could be used The primary considerations are 1 that the coil hold the line when connected across tip and ring of the line and 2 that a satisfactory low frequency null is achieved with the coil connected In no case should a resistor be used to hold the line since this would shift the impedance of the line such that the TI 101 cannot effectively null What should the signal be that I apply to the SEND INPUT of the 101 The signal should be everything you want the caller the person on the other end of the phone line to hear except 1 The caller s voice which has come from the RECEIVE OUTPUT of the TI 101 Including this would give the caller an objectionable echo of his own voice This means you should not use the total mix from the output of your mixing board since this contains the caller s voice Rather assign all mic signals to another bus or patch off the mic preamp output to derive the send input signal 2 Other callers voices if the
20. onsole or mixer so that you can monitor the return from the phone line the TI 101 s caller output Have your assistant on the other end of the phone line speak to you at normal conversational volume Turn up the receive level control on the TI 101 until a good receive signal is obtainable using the O dB reference as a starting point You should now be hearing your assistant s voice returning through your console or mixer clearly and without distortion 6 4 HYBRID NULL ADJUST Next you will adjust the null Ask your assistant to place the telephone receiver in a quiet place and not to make any noise for a few moments Speak into your microphone and adjust the front panel COARSE NULL potentiometer for the minimum signal receive signal in your monitors Continue speaking into the microphone and adjust the LF and HF potentiometers As you make these adjustments be sure that the send or receive circuit clip lights are not coming on The null degrades if either of these circuits are driven into clipping The LIMIT and COMPRESS EXPAND THRESHOLD controls will be adjusted to help prevent this from happening as described in the next section 6 5 SEND LIMITER You are now ready to adjust the SEND LIMIT threshold control With the telephone connection made shout into your microphone Make sure that you are not overloading the input to your mixer or clipping its output As you shout you should observe the send CLIP LED flashing Adjust
21. te the above three situations like any other feedback can sometimes be cured by the judicious application of narrow band EQ of the monitor not main signal 4 The telephone and signal is being clipped This degrades the null and is indicated by the flashing of the CLIP LED on the send sections of the TI 101 How I get more RECEIVE OUTPUT level from the TI 101 1 Change the rear panel switch from 10 dBm to 8 dBm 2 Decrease turn counterclockwise the RECEIVE EXPAND COMPRESS THRESHOLD control 3 Apply gain in the unit following the 101 What telephone load is the 101 designed to be connected to For effective nulling the TI 101 should be connected to the same line for which it was nulled or possibly to sequentially numbered lines on the same exchange This would rule out connecting it after rotary line selectors or key sets if the lines to which they are connected are of different 3 04 Page 25 For Assy Part 9945 3 06 601 Heron Drive Logan Township NJ 08085 Phone 856 467 8000 Fax 856 467 3044 http www radiosystems com
22. the send threshold control counterclockwise until the LED is no longer lit You should now be at the optimum operating send level Make sure no one changes these settings 3 04 Page 12 Radio Systems Inc TI 101 Manual 6 6 COMPRESS EXPAND THRESHOLD Now ask your assistant to shout back at you Adjust the COMPRESS EXPAND THRESHOLD control in the counterclockwise direction You will notice an increase in the volume level as you adjust this control Compensate for this by decreasing the RECEIVE LEVEL control slightly If you continue to adjust the COMPRESS EXPAND THRESHOLD in the counterclockwise direction you will start to notice the effects of the expander Any of the noise on the phone line will be attenuated during the pauses in the conversation Adjust the settings of this threshold control until you get the desired effect Remember that if you set this threshold control too low then you run the risk of cutting off your caller if he she speaks weakly A little experimentation with different callers should help determine the optimum setting 6 7 EQUALIZATION Finally have your assistant read something As he does adjust the equalization section of the TI In general some boost of high frequency 2 5 kHz is always helpful for improving intelligibility However adjust both controls to suit your taste 3 04 Page 13 Radio Systems Inc TI 101 Manual 7 USING THE CONFERENCE MODE CONFERENCE FEATURE USE OF 2 TI 101 S TO CONFE
23. ut is run to another line input of the air console so the studio level and the caller level can be controlled separately 3 04 Page 22 Radio Systems Inc TI 101 Manual 10 4 USING THE CUE BUS OF AN EXISTING MIXING CONSOLE Where there are enough extra line inputs available on the existing air console use the following technique The input used for the studio mic is switched to the cue or audition bus Assuming the caller is not put on cue the cue bus output will be a mix minus signal because it contains only the signals from the studio microphones It can therefore be used to feed the host audio input on the TI 101 In addition the cue bus output is routed to the air bus through a separate line input on the console so the studio mic can be heard on the air To complete this technique the TI 101 s caller audio output is returned to the console through yet another line input to the air bus only providing separate level controls for both the studio host and the caller 3 04 Page 23 Radio 11 Systems Inc TI 101 Manual COMMON QUESTIONS AND ANSWERS Below are listed some of the most often asked questions about connecting the 101 How do I seize the telephone line if I don t have a telephone set connected in parallel with the TI 101 The telephone company uses the DC current flowing between tip and ring to sense off hook condition Since the TI 101 is AC coupled to the line it will not seize the line Basical
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