GV-298 Manual
Contents
1. 45 4 3 6 2 Tuning by frequency 46 4 3 6 3 RF signal attenuation 46 4 3 6 4 Intermediate frequency 47 4 3 7 Error messageS II KAA Wa ees 47 4 3 8 Output description 20 2244 AA A ee eee a aa a 48 4 3 8 1 Composite video output 48 4 3 8 2 EUFOCONNECION a 2 06 Hack deal WEES aa nd E 48 4 3 8 3 Trigger oscilloscope 48 5 OPERATION PRINCIPLE 49 5 1 Synchronism generator 49 5 2 Control logic and colour generation 49 53 SOU GA Kee ad Racketeer Peale ERA ayer ds ata Rome h 49 5 4 Radiofrequency unit 49 5 5 MiCrOCONTTOlSE xo P4440 See bade hh be eet bee ea dde G24 Ge pede 50 6 MAINTENANGE 202 2004 8 AA Bi eee Bee toe DA 53 6 1 Replacing the mains fuse 53 6 2 Cleaning recommendations 53 09 96 GV 2982. 13 14 15 16 17 09 96 40 CHAN Display area designed for showing that channel tuned When the selected frequency does not belong to any channel as implemented in the equipment this area is blank TV channels are designated with a C and a number for instance channel 41 is C41 Cable TV channels are designated with an S say S11 Implemented channels depend on version chosen Channel selection LED indicator When this LED is on the selected channel DN di can be changed by pressing key 12 increase or 13 V decrease FREQ MHz Display area designed for showing frequency Frequency is displayed with 5 digits two of which are decimals Frequency selection LED indicator When this LED is on frequency tuned can J be changed by pressing key 12 gt increase or 13 V decrease in steps of 50 40 dB attenuating cell On pressing this key a 40 dB attenuation is entered AN in the radiofrequency output RF 750 11 20 dB attenuating cell On pressing this key a 20 dB attenuation is entered in the radiofrequency output RF 75Q gt 11 RF 752 Modulated radiofrequency output Composite video signal modulates the radiofrequency RF carrier in negative amplitude and at double side band Impedance is 75 Q Increasing key 4D The next information is shown in the active area of the display 2 l Decreasing key V The former information is shown in the a
3. CAUTION Do not use scented hydrocarbons or chlorized solvents Such products may attack the plastics used in the construction of the cover The cover should be cleaned by means of a light solution of detergent and water applied with a soft cloth Dry thoroughly before using the system again 09 96 GV 298 28 09 96 GV 298 29 TABLE OF CONTENTS GENERAL Wa toana ias a a ie ened ates AA RLS te Ma Be fe Ae sig o a i de 31 TA DOSCHIPUON ia AA wlohe tes id We PEC ah to OE AR A fe 31 1 2 SPechiiCaliOns y ins wes Ea A SE WAS te Ae A eR 32 2SAFETY RULES Satoh Saco AA mate ee Ses oe aca ee fet a Bie at Re eee 35 3 INSTALLATION ur na ona os 37 3 1 Power requirements 37 3 2 Installations i eaa A a a Eee hee a ER 38 4 OPERATING INSTRUCTIONS 39 4 1 Description of controls 39 4 2 Slane PRERE ELELEE ETATER EEEE OE ea eso hen 41 4 3 Using the equipment 42 4 3 1 Display and keyboard 42 4 3 2 Outputisignal 25 6 220444 IAA e nt laa 43 4 3 3 Pattern selection 43 4 3 4 Test pictures application 43 4 3 9 FUNCION Keys osa a Sal by Ae a ee e ag eee pf aca a 44 4 3 6 Radiofrequency stage 45 4 3 6 1 Tuningbychannel
4. key 10 pushed 40 40 key 9 pushed 60 20 40 keys 10 and 9 pushed With a 40 dB 300 uV attenuation a properly adjusted TV set usually shows a snow effect picture 4 3 6 4 Intermediate frequency Intermediate frequency used in TV sets is 38 9 MHz In the GV 298 this carrier is achieved by selecting a channel see 4 3 6 1 or a frequency see 4 3 6 2 Intermediate frequency tuning by channel requires moving towards that first expected channel just before C02 Then the display will show IF together with frequency related to This configuration allows a modulated signal to be supplied to the I F stage input of the receiver This signal may be used to check whether the noticed failure is due to the tuner or to a later stage 4 3 7 Error messages The GV 298 builds in a microcontroller ready to detect a defective running of some equipment devices As soon as an abnormal behaviour is found an error message is displayed in the following format ERROR XX Where XX is that number designing the kind of failure arisen for instance ERROR 00 An error message will vanish on pressing either key 12 13 or 14 If error persists that warning will appear again while the equipment is running In such a case please contact your distributor telling him the message shown by the GV 298 Every time the GV 298 is connected the unit performs an AUTOTEST in order to check its proper operation If an error is sensed
5. TV PATTERN GENERATOR GV 298 1 GENERAL 1 1 Description The exceptional attributes the GV 298 video generator consists of have been designed in accordance with the latest trends of modern technology Its application field is ranging to every use in which a professional feature is requested such as to achieve the hardest requirements both in the synchronism step and the colour and radiofrequency ones User friendly compact and strong the GV 298 is a specified tool for all servicing needs The GV 298 will become a consummate partner for after service professionals both in workshop tasks and home repairs and fittings Eight different pattern charts are available allowing essential settings to be made in any television receiver as well as to detect abnormalities through a visual picture examination Besides these equipment builts in four additional functions to be connected or disconneted at will in every chart This monitoring affects picture interlacing chroma subcarrier sound and PAL commutation The synthesized RF modulator ranges from 37 MHz to 865 MHz so any defect in tuning circuits or in the IF of the receiver can be detected Tuning is performed by channel CCIR OIRT or FCC channes depending on version or directly by frequency in 50 kHz steps A two cell attenuator allows up to a maximum of 60 dB to be attenuated in 20 dB steps A microcontroller carries out the interaction with the user by displaying chart channe
6. UROCONNECTOR GV 298 34 R G B OUTPUTS Amplitude 0 7 Vpp Output impedance 75 Q Connector EUROCONNECTOR TRIGGER OUTPUT FOR OSCILLOSCOPE Signal Vertical Horizontal Amplitude 2 Vpp vertical 1 5 Vpp horizontal Output impedance 5 ka Connector BNC LOW FREQUENCY OUTPUT Amplitude 250 mVpp Frequency 1 kHz Output impedance 10 kQ Connector EUROCONNECTOR POWER SUPPLY Mains voltage 110 125 220 230 240 V AC 10 50 60 Hz Consumption 8 W OPERATING ENVIRONMENT CONDITIONS Max altitude 2000 m Temperature range From 5 C to 40 C Max relative humidity 80 up to 31 C decreasing lineally up to 50 at 40 C PHYSICAL FEATURES Dimensions W 102 x H 90 x D 241 mm Weight 2 250 kg ACCESSORIES INCLUDED 90901207 BNC TV coaxial cable CC 07 90901105 Mains cable CA 05 Spare fuse 5 x 20 mm 250mA F 250V VERSIONS GV 298 PAL B G H CCIR channels GV 298 2 PAL DK OIRT channels GV 298 4 PAL I CCIR channels GV 298 6 PAL N FCC channels 09 96 GV 298 35 A 2 SAFETY RULES ZA This is a class equipment for safety reasons plug it to a supply line with the corresponding ground terminal Use this equipment only with systems or devices with the negative measuring connected at ground potential or insulated from the mains This equipment can be used in Category Il Instalations and Pollution Degree 1 environments When using some of the following accessories use only the specified ones to ensure
7. ction keys enabled and system chosen PAL giving rise to the three basic signals R G and B From them luminance is issued identified as Y in the block diagram R G and B are carried to the colour module which builds signals R Y and B Y These are used to square modulate the colour subcarrier which frequency is settled by the system used Video signal is generated from luminance and chrominance by a submodule generator This signal is carried through a stage in order to give a 75 Q output impedance to the video signal After crossing a suitable output stage R G and B signals are present in the EUROCONNECTOR 5 3 Sound The low frequency oscillator generates a 1 kHz signal used for sound modulation A carrier frequency of which is specified by that standard used is frequency modulated by the low frequency signal and carried to the RF unit The 1 kHz signal is carried through an output stage to fit it with a suitable impedance then this signal is switched to the EUROCONNECTOR 5 4 Radiofrequency unit Function of the radiofrequency unit is to modulate both video and sound signals with a user s selected frequency carrier This unit is synthesized in order to ascertain a minimum drift in that signal supplied by the GV 298 An attenuation unit allows that level supplied by the RF unit to be varied in a O dB 20 dB 40 dB and 60 dB scale 09 96 GV 298 50 5 5 Microcontroller This component operates interaction b
8. ctive area of the display 2 SEL Selection key to select the display active area 2 Upon selecting the active area the displayed current information can be changed by pressing key 12 4 increase or 13 V decrease SOUND This key enables the sound subcarrier On pressing this key the sound subcarrier comes out frequency modulated by a 1 kHz signal NOTE Low frequency signal in pins 1 3 of the EURO AV 21 Euroconnector is unable to be removed because the SOUND key 15 acts on the carrier only INTERLACED On pressing this key the interlacing is removed PAL PAL switching suppression key On pressing this key that typical PAL system R Y signal is removed GV 298 41 18 CHROMA Colour subcarrier suppression key to remove colour subcarrier fully 19 VIDEO 75 Q 1 Vpp Composite video output with 1 Vpp amplitude and positive bias Output impedance is 75 Q Typ GV 298 O 0 E 50 60Hz Figure 3 Rear panel 20 Mains input set 21 EURO AV Euroconnector 22 TRIG SCOPE A Composite signal output for trigger oscilloscope 4 2 Start up Once mains voltage to be used has been selected point 3 1 the unit can be switched to mains and started up by pressing the LINE switch 1 09 96 GV 298 42 4 3 Using the equipment This section explains how to use the GV 298 including keyboard operation composite video signal radiofrequency error messages information appearing on the
9. display is detailed as well 4 3 1 Display and keyboard Figure 4 Depending on information shown the display 2 may be divided in three areas The first area PAT 3 displays that pattern currently operating Value shown in this area is any one of those letters specifying the pattern charts as drawn on the GV 298 front panel The second area CHAN 5 displays the channel tuned If a selected frequency does not belong to any channel implemented in the equipment this area is blank Otherwise the number of the channel tuned is displayed Finally the third area FREQ MHz 7 is designed to display the tuned frequency in MHz with 5 digits two of which are decimals 09 96 GV 298 43 A LED is provided just under each of these three areas described Function of key SEL 14 is to enable one among these LED every time it is pressed In this way by pressing it recurrently LED are lighted on sequentially The enabled LED shows which display area is active e the current information can be changed by pressing key 12 lio increase or 13 Y decrease 4 3 2 Output signal In using the GV 298 two different ways may be discerned a Use of the composite video signal b Use of the radiofrequency RF stage All parameters adjusted for the composite video signal are valid for the modulated RF signal Current R G and B signals in the EURO AV Euroconnector 21 have fixed amplitude These outputs ca
10. e following sequence Line Frame 1234 Even Odd t 5 32 ON OFF selectable 3 as related with red colour amplitude 100 saturated Digital 16 characters 5 digit frequency display channel TV standard programme pattern chart and sound system GV 298 TEST PICTURES Pattern charts available 1 100 white pattern 2 Electronic circle grid 3 Dots 4 Checkboard 5 Colour bars 6 Red pattern 7 Green pattern 8 Blue pattern 33 Anti PAL pattern by removing the R Y switching RADIOFREQUENCY OUTPUT Range Tuning Output amplitude Attenuator Output impedance Connector STABILITY At constant temperature At temperature FREQUENCY INDICATOR Indicator Resolution VIDEO MODULATION Modulation type Modulation index Video sound ratio SOUND MODULATION Carrier frequency Modulation type Drift MODULATION SIGNAL Internal Frequency COMPOSITE VIDEO SIGNAL Amplitude Bias Output impedance Connector 09 96 From 37 to 865 MHz synthesized By frequency in 50 kHz steps By channel CCIR OIRT version 2 FCC version 6 80 dBuV 3 5 dB 0 60 dB in 20 dB steps 750 BNC lt 1 2 x 10 10 min the first 15 min lt 4 x 10 10 min during the first hour lt 1 x 10 2C 5 to 40 C In the 5 digit LCD display 50 kHz AM double side band 85 13 dB 5 5 MHz ON OFF selectable FM 30 kHz 1 kHz 10 1 Vpp Positive 75 Q BNC and E
11. ed for cable TV signals transmission 4 3 6 2 Tuning by frequency Within the frequency range of the equipment 37 MHz to 865 MHz any frequency may be tuned in 50 kHz steps In this way any tuning may be approached even if it does not belong to any specified channel On pressing key SEL 14 sequentially the FREQ MHz 8 indicator LED will light on Next to frequency to be tuned can be modified by using keys 12 4 J 7 increase or 13 V decrease When the tuned frequency matches a channel the display will read the number and type of that channel In the event that tuned frequency does not match any channel as specified by the equipment no indication will be displayed Since the modulation system is using a double side band two apparently right tuning points can be found This does not happen on tuning a TV station as system used is a partially suppressed lower side band In order to decide which from the two points is the right one this suits with the higher frequency if tuning is done with a TV set On the contrary it suits with the lowest frequency when tuning through the generator 4 3 6 3 RF signal attenuation To check automatic gain control circuits of TV sets a two cell one 20 dB cell and one 40 dB cell attenuator has been built in in order to attenuate the RF output if required Maximum total attenuation is 60 dB in 20 dB steps 09 96 GV 298 47 dB ATTENUATION CELLS ENABLED 00 None 20 20
12. etween the GV 298 and the user directing the display and the keyboard This microprocessor gives relevant commands to the RF unit and to the control logic module in order to generate a suitable signal to user s requirements 09 96 GV 298 51 9 Bi 86 c AD GOW WVeYSVId 19019 H Hakika wl la s u ld H H H H INALNO su 0 dE VOJAIA YOLVNNALLV Ate J NSL YATIOULNOOSOUOIN LINN AS Yoy TOSO YHOLVTIIOSO AS e 1Ndino Ju ZHN S S 37ZHA L AZL y g 9 y NOLIVE3N39 O INdINO aaay NH3 LlYd o3dIA OAGIA A ad 8 TOHLNOO 91901 g D Y Ha na 229097 UIHUVIANS YOLVINGOW 4 HOLVe83N30 yno109 ano 109 1 8 A 8 Tid WSINOHYHONAS YHOLVYANSD 3194819 GV 298 09 96 52 09 96 GV 298 53 6 MAINTENANCE 6 1 Replacing the mains fuse The fuseholder lid is placed in the mains base see figure 1 and it is the voltage selector To substitute the fuse disconect the power cord With an appropiate screw driver remove the fuseholder lid Substitute the melt fuse for another of FUSE TYPE SHOULD BE 5 x 20 mm 250 V F and 250 mA FOR ALL VOLTAGES AVOIDING THIS DIRECTIONS COULD DAMAGE THE EQUIPMENT When inserting the fuseholder lid be careful that the voltage selector is in the correct position according to the mains 6 2 Cleaning recommendations CAUTION To clean the cover take care the instrument is disconnected
13. f a screen colouring appears in such conditions it should be charged to a defective working in some stage or in some cases to a excess of gain of chroma amplifiers 4 3 6 Radiofrequency stage Radiofrequency RF carrier is modulated by the composite video signal in negative amplitude and double side band This signal is available at the RF Ce connector output 11 Impedance is 75 Q Frequencies selected by the user are programmed into the RF unit by a microprocessor Frequency tuned is displayed at any time Tuning is performed in two ways whether by channel or by frequency directly 4 3 6 1 Tuning by channel The GV 298 pattern generator is carrying out a great number of standard channels easy to access through the keyboard On pressing key SEL 14 repeatedly the CHAN 6 LED indicator will light on In this condition the display shows C JA channel may be changed Increasing A 12 key or decreasing Nya key 13 are used for channel varying The selected channel will then be displayed together with its frequency The following table lists both channels frequency ranges and TV bands assigned Ground version CCIR channels 09 96 GV 298 46 Band Frequency range Channels IF 38 9 MHz IF IB 47 65 MHz 2 4 MIDDLE 104 174 MHz S1 S10 B Ill 174 230 MHz 5 12 SUPER 230 300 MHz 11 S20 HYPER 302 468 MHz 21 S41 B IV 470 606 MHz 21 37 BV 606 854 MHz 38 69 NOTE S channels are us
14. int 1 2 Specifications 4 3 8 3 Trigger oscilloscope When a TV set circuits are analyzed with the help on an oscilloscope desynchronization due to amplitude differences of signals watched is not desirable as is the case when synchronism is done internally To get a quite synchronized picture regardless of signal amplitude the external synchronism input of the oscillospe should be used connecting same to the TRIGG output of generator GV 298 connector SN TRIG SCOPE 7 22 If the oscilloscope has as all PROMAX types have a TV automatic filter connected to the time base switch then passing from the horizontal frequency to the vertical one can be made without synchronism loss In this output horizontal pulses are mixed with higher amplitude vertical ones thus providing the oscilloscope to be synchronized to vertical frequency 09 96 GV 298 49 5 OPERATION PRINCIPLE This chapter is an overview of the GV 298 operation Explanation lies in block diagram of Figure 6 at the end of this chapter 5 1 Synchronism generator The synchronism generator supplies two significant signals in order to allow GV 298 output to be viewed through a TV set these two signals are the horizontal and the vertical synchronisms The first one commands a line changing in the TV set while the second one starts a screen sweep 5 2 Control logic and colour generation This module generates a video signal according to the pattern selected the fun
15. l and frequency 5 digits at any time on a 16 character display Data displayed may be changed in an easy way by means of three pushbuttons In order to increase quality and reliability of the GV 298 the built in microprocessor carries out a checking of several equipment devices during its connection and use An Euroconnector is included as well as an oscilloscope synchronizing output This equipment is intended for covering B G and H standards CCIR Versions are available too for 1 DK and N systems 09 96 GV 298 1 2 Specifications A TV SYSTEM System RF standard Line frequency Frame frequency Horizontal synchronism Line period Previous pedestal Synchronism Blanking Vertical synchronism Frame period Blanking Pulse time of Pre equalizing Equalizing Post equalizing Frame sweep Colour subcarrier Subcarrier frequency Burst duration Burst position Phase Amplitude error Phase error Subcarrier amplitude Residual subcarrier DISPLAY 09 96 32 CCIR PAL B G H DK I N on request 15625 Hz 50 Hz 64 us 0 0002 us 1 5 us 03 us 4 7 us 0 2 us 12 us 0 3 us 20 ms 25 H 12 us H 64 us 25H 25H 25H Selectable 2 1 interlaced ratio No interlaced F 4 3361875 MHz lt 30 ppm PAL B G H DK l F 3 582056 MHz lt 30 ppm PAL N 10 C to 40 C 2 5 us 10 1 F period At 5 6 us from the line previous synchronism flank 135 as referred to U axis at th
16. nnot be used for analyzing the Anti PAL signal since it is a natural characteristic of this signal that it affects the colour subcarrier CAUTION To achieve a right operation of the GV 298 when an output is connected to an external unit make sure impedances are suited correctly as specified in point 1 2 Otherwise a wrong operation could be noticed 4 3 3 Pattern selection To select a pattern the PAT 4 chart selection indicator LED should be enabled To this end press key SEL 14 sequentially Next to that letter suiting with Le op the required chart will be displayed by pressing pushbuttons 12 7 increase or 13 SZ decrease 4 3 4 Test pictures application Patterns are assembled in two rows showing affinity in use Top row including four patterns intended for adjusting B W parameters A 100 white screen Checkup of the beam current limiter circuit Video recorders modulation adjustment and signal to noise ratio measurements B Circle grid Adjustment of static and dynamic convergency Interlacing checkup Adjustment of aspect ratio and picture centering in the screen Adjustment of picture geometry and linearity through the electronic circle C Dots Focus voltage adjustment 09 96 GV 298 D 44 Checkboard Video amplifier response analysis at low frequencies A white level pulse is yield by all pattern charts just before the previous sweep pedestal This component allows video signals t
17. o be surveyed through the oscilloscope as the line change is displayed just at the time it arises This pulse cannot be seen in a conventional receiver for it is hidden behind the right side of the screen Bottom row including four patterns intended for adjusting the colour stage 100 white bars Checkup of colour matrix saturation etc Red screen Purity control of red colour R noise and beam current Green screen Purity control of green colour G noise and beam current Blue screen Purity control of blue colour B noise and beam current 4 3 5 Function keys 09 96 Keys 15 to 18 allow some pattern capability to be extended in order to enlarge their application field Specification of these additional functions follows 15 16 17 SOUND This key enables the sound subcarrier On pressing it the sound subcarrier is frequency modulated by a 1 kHz signal This subcarrier frequency varies depending on which system the GV 298 has been fitted for 5 5 MHz for PAL B G and H GV 298 ground version 6 MHz for PAL GV 298 4 version 6 5 MHz for PAL DK GV 298 2 version and 4 5 MHz for PAL N GV 298 6 version NOTE Low frequency signal in pins 1 3 of the EURO AV 21 Euroconnector is unable to be removed because the SOUND key 15 acts on the carrier only INTERLACED Interlacing cancellation This function is useful when adjusting convergencies In the grid pattern horizontal lines are shaped by
18. r fuse for the desired mains voltage 3 Insert the fuseholder lid so the A pointer faces the desired mains voltage display B 09 96 GV 298 38 CAUTION THE EQUIPMENT IS FACTORY SET FOR 220 V OPERATING VOLTAGE BEFORE SWITCHING ON THIS INSTRUMENT SET THE VOLTAGE SELECTOR TO THE PROPER POSITION AND BE SURE THAT THE FUSE VALUE IS CORRECT FUSE TYPE SHOULD BE 5 x 20 mm 250 V F and 250 mA FOR ALL VOLTAGES AVOIDING THIS DIRECTIONS COULD DAMAGE THE EQUIPMENT 3 2 Installation This unit is ready to be used as a desk top equipment 09 96 GV 298 39 4 OPERATING INSTRUCTIONS 4 1 Description of controls Cal 1471 25 aa mea we VIDEO FUNCTIONS 75 Q 1Vpp m OFF CHROMA PAL LACED SOUND Lo BEGG aa Saana gt 90 9 18 17 8 15 19 3 3 1 Figure 2 Front panel 1 LINE Mains switch 2 LCD display This display shows pattern chart selected channel and frequency In the event of a malfunction this part will display an error code 3 PAT This area is designed for chart displaying The several charts are specified by a letter as drawn on the front panel 4 Chart selection LED indicator When this LED is on the selected chart can be t changed by pressing key 112 4 ir increase or 13 gt decrease 09 96 GV 298 5 6 7 8 9 10 11 12
19. safety Power cord Observe all specified ratings both of supply and measurement Remember that voltages higher than 60V DC or 30V AC rms are dangerous Use this instrument under the specified environmental conditions The user is only authorized to carry out the following maintenance operations Replace the mains fuse of the specified type and value On the Maintenance paragraph the proper instructions are given Any other change on the equipment should ve carried out by qualified personnel The measuring negative is at ground potential Follow the cleaning instructions described in the Maintenance paragraph 09 96 GV 298 36 Symbols related with safety gt gt Bo stsisOitae il 09 96 DIRECT CURRENT ALTERNATING CURRENT DIRECT AND ALTERNATING GROUND TERMINAL PROTECTIVE CONDUCTOR FRAME TERMINAL EQUIPOTENTIALLITY ON Supply OFF Supply DOUBLE INSULATION PROTECTED Class Il Protection CAUTION Risk of electric shock CAUTION REFER TO ACCOMPANYING DOCUMENTS FUSE GV 298 37 3 INSTALLATION A 3 1 Power requirements A This equipment requires a mains power source of 110 125 220 or 230 240 V AC 50 to 60 Hz Mains operating voltage can be selected at the rear panel To remove the fuseholder lid insert a little screwdriver in the slot and lift out Fuseholder lid Figure 1 Selection of mains voltage 1 Pull out the fuseholder lid 2 Setthe prope
20. the display will show AUTOTEST FAILED which means some failure is arising In this case like formerly your distributor should be contacted 09 96 GV 298 48 4 3 8 Output description 4 3 8 1 Composite video output Positive composite video signal can be drawn through connector BNC VIDEO gt 19 on the front panel with 1 Vpp amplitude and 75 Q output impedance This signal is very useful for checking video monitors B W and color line amplifiers VCR and any other equipment working with a composite video CAUTION This signal should never be switched to voltage circuit points but only on video signal standardized inputs with 75 Q impedance Damages arisen in the unit ensuing from neglecting this caution are not covered by warranty 4 3 8 2 Euroconnector EN50049 DIN connector Generator GV 298 is provided with an EUROCONNECTOR type connector also known as SCART connector or PERITEL connector according to NF C92250 standard Output signals from this connector are PIN NUMBER SIGNAL pi 4 q Biss 1 3 1 kHz sound output T ES 1 4 Sound ground eae 5 Blue ground B ee 7 Blue output B WA 8 12 V switching output ma nai 9 Green ground G pap en 11 Green output G pn Pe 13 Red ground R i co 5 15 Red output R eae 17 Composite video ground ra l 19 Composite video output pea S 21 Connector shield ground Figure 5 Description of EYROCONNECTOR switching pins For more information see po
21. two white lines one from the even frame the other from the odd one If this pattern is watched from a close position to the screen flickering is very pronounced Thence user would have it easier to remove interlacing in this way that flickering is removed too Besides interlacing suppression allows the vertical integration system of the synchronism separator to be verified PAL In a standard operation of a colour pattern the GV 298 will transmit component R Y and B Y in one line and component R Y and B Y in the next line i e signal R Y is switched in each line but component B Y is kept constant This process concerns both chroma vectors and burst which is eventually telling the receiver how to switch the R Y signal sensed in order to retrieve the source colour signal GV 298 45 On pressing key PAL R Y switching PAL system typical is suppressed Anyhow as the burst switching is kept the receiver will perform the R Y switching further As a result no signal at all will come out at the R Y demodulator output if the receiver is adjusted correctly On a properly adjusted TV set lack of R Y component can be observed in the colour bar signal picture without PAL switching 18 CHROMA The colour subcarrier may be suppressed fully In this way luminance can be analyzed in colour patterns Lack of chroma in the transmitted signal shall enable the colour killer circuit of the receiver Therefore i
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