JBL 6810 User Manual Download

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Professional

Video

Products

TECHNICAL

TRAINING MANUAL

MODEL 6810 AND 6820

VIDEO PROJECTOR

JBL International

8500 Balboa Blvd.

Northridge, CA 91329

( 8 1 8 ) 8 9 3 - 8 4 1 1

JBL

Summary of Contents for 6810

Page 1: ...Professional Video Products TECHNICAL TRAINING MANUAL MODEL 6810 AND 6820 VIDEO PROJECTOR JBL International 8500 Balboa Blvd Northridge CA 91329 818 8 9 3 8 4 1 1 JBL...

Page 2: ...tching Circuits 25 Insert Video Switching Circuits 25 Sound Processing Module Stereo Amplifier 26 Comb Filter Module 28 Video Processor Panel 30 Auto Sharpness Control 30 Video Processing Circuits 31...

Page 3: ...Figure 1 Signal Flow Block Diagram...

Page 4: ...Audio Volume Bass and Balance controls adjust the drive to the Stereo Power Amplifier Detected Video from the IF Module is fed through the Tuner Interface Panel J32 to I O Panel J707 the Tuner Video I...

Page 5: ...Regulator and therefore the output voltage by means of Pulse Width Modulation PWM The 130Vdc output from the Switched Regulator is fed to the Deflection Panel and High Voltage Regulator The High Volt...

Page 6: ...ives the Horizontal sweep circuits and the Switched Regulator on the Power Supply Panel R5 and C10 form a two second timing circuit C10 begins to charge toward 42Vdc after the Power button is pressed...

Page 7: ...R35 and to provide collector voltage to the 130V Switching Regulator Q10 The regulated voltage at Q10 emitter and Test Point TP7 is adjusted to 130Vdc with RP1 B Adjust The 130Vdc appears across an R...

Page 8: ...ge decreases or increases If the scan derived 10Vdc decreases the decreased voltage at RP2 wiper and IC2 2 causes the Comparator IC2 6 output to rise and turn Q13 On harder raising Q13 and Q12 emitter...

Page 9: ...an Pulse Rectifiers D15 through D20 The circuits of the Horizontal Oscillator Module are shown in Figure 8 The internal function of IC1 are Sync Separator Video Amp AGC Noise inverter Phase Shaper Pha...

Page 10: ...31 5KHz pulses are also applied to a Divide by 2 Counter to produce the Horizontal Drive signal If the Sync pulses fed to IC2 13 are not standard NTSC Sync the Mode Recognition switches from the Divid...

Page 11: ...in Figure 11 switch Off the 130Vdc supply when excessive current is sensed in the 130Vdc supply L2 on the Deflection Panel During normal operation the 10Vdc EHT Reference voltage is fed from Power Pan...

Page 12: ...omponents of this system are the 178 channel Controller the Tuner and the Tuner Interface Panel The Controller uses an 8 but Microcomputer a CITAC IC a Micro processor with internal ROM for processing...

Page 13: ...s the Microcomputer alive during the power Off periods and maintains the Last Channel Viewed and Volume Level memories The chassis is powered On by a microcomputer controlled relay The CITAC IC contro...

Page 14: ...Blanking is developed by adding Vertical pulses to the Horizontal pulse line through Inverter Q21 Blanking is then coupled to the Graphics Generator on the Controller R G and B Graphics Video signals...

Page 15: ...Figure 14 TS10 Tuning System Block Diagram...

Page 16: ...RF Switcher Antenna input IC1000 22 turns On Q340 with a logic High to provide a ground through CN1300 6 and RF Switcher J52 1 for the switching diodes the switched On diodes D1 and D3 couple the RF s...

Page 17: ...able from the Tuner is connected to the If Module at J1 The Adjacent Channel Sound signal is trapped at 47 25MHz by C1 L2 then the signal is amplified by Q1 and fed to SAW Filter F1 where two bandpass...

Page 18: ...is buffered and applied to the Pilot Detector and the Automatic Frequency and Phase Control AFPC circuit The AFPC circuit compares the phase of the Pilot signal with the phase of the local Oscillator...

Page 19: ...the 4KHz to 9KHz band of frequencies is coupled to RMS detector B A variable dc voltage is developed by the de tector which is proportional to the average level of the Audio frequencies within the pas...

Page 20: ...Figure 20 Decoder Module Signal Flow Diagram...

Page 21: ...output at Pin 8 and amplified by Q3 The signal is then passed through a 0 to 12KHz lowpass filter to Pin 6 of IC4 The amplified SAP signal is output Pin 7 taken from the arm of the Level Adjust contro...

Page 22: ...ISTEREO EXPAND QUASI I F MODULE VIDEO PRE AMP SAWFILTER VIDEO DETECTOR EQUALIZER OUTPUT BUFFER AUDIO DETECTOR SAP AUDIO OUTPUT VIDEO OUTPUT COMPOSITE SYNC HORIZONTAL PULSE COINCIDENCE DETECTOR Figure...

Page 23: ...19 is High and turns On Tuner switch Q2 The tuner switch outputs an emitter High to Input Output Panel J715 1 from J911 5 to be used as the control voltage for the Tuner Video and Audio Switching Inpu...

Page 24: ...de A High about 12Vdc is fed to the I O Panel J715 from the Tuner interface Panel The 12Vdc applied to IC3 5 and 13 turns On the Tuner Audio switches IC3 3 to 4 and IC3 1 to 2 Decoded TV Audio from th...

Page 25: ...Green Blue Video Output Jacks J703 J702 J701 n D Con nector Red Green Blue Input Q9 Q10 Red Video Amplifier Q15 Q16 Green Video Amplifier Q13 Q14 Blue Video Amplifier Q34 Q33 Intensity Bit Amplifiers...

Page 26: ...mputer Insert Video Switching Circuits Some accessory devices such as decoders for Teletext Videotext and RGB computers output special RGB Video and Blanking signals used to insert information within...

Page 27: ...14 outputs 12Vdc which turns On the Mono switch Q8 D5 becomes forward biased and couples 12Vdc to the Sound Processing Module Left and Right Audio signals from the Input Output Panel J718 4 1 are fed...

Page 28: ...r Audio Power Outputs IC301 and IC302 A full wave power supply de velops 15Vdc which is regulated to 8Vdc by zener Z401 IC201 is powered by the 8Vdc supply Also Q201 and Q202 Mute Drivers use the 8Vdc...

Page 29: ...ds it to Q4 base The Vertical Detail Buffer Q8 drives Q6 with 0 5Vpp Vertical Detail signal to replace vertical resolution lost during the Video combing process Q6 Vertical Detail gain is adjusted wit...

Page 30: ...Figure 31 Comb Filter Module Figure 32 Comb Filter Circuit...

Page 31: ...stle and IC4 RGB Processor The transistors and their functions are Q14 Q20 Video Amp lifier Q15 Q16 Q17 Video High Frequency Amplifiers Q13 Q18 Blankers Q22 Q23 Chroma Amplifiers Q25 Clamp Pulse Buffe...

Page 32: ...l The normal setting for good flesh tones is about 2Vdc Internal matrixing of the demodulated Chroma and the dc restored Video with Blanking added develops the 4Vpp R G and B Video signals fed to the...

Page 33: ...rs Q39 and Q40 to IC4 20 to restore Vertical and Horizontal Blanking to the Video signal for CRT blanking Black level is a preset dc voltage adjusted by Sub Brightness control RP4 which is a preset dc...

Page 34: ...with 10OVpp Sync positive Video When the set is turned Off or when ac power is interrupted or when Horizontal and Vertical sweep voltages are removed because of a shut down condition the CRT beam curr...

Page 35: ...Figure 37 CRT Drive Circuit 4...

Page 36: ...block diagram of the convergence circuits is shown in Figure 39 The main circuits are the Horizontal Ramp Generator power source for the Panel Customer Control Panel five waveform generators six Conve...

Page 37: ...SSHAIR GENERATOR J604 I C I HORIZONTAL WAVEFORM AMP CONT I C 3 TOP BOT PINCUSHI CORRECT i TOM ON OR IC4 VERTICAL WAVEFORM AMP CONT I C 2 TRAPEZOID KEYSTONE GENERATOR I C 5 SIDE PINCUSHION CORRECTOR CO...

Page 38: ...tal waveform circuits is shifted by RP1 which positions the Crosshair pattern vertical line in the center of the raster Convergence Panel Voltage Source The 16Vdc and 16Vdc from the Deflection Panel J...

Page 39: ...at IC4 7 TP12 Both waveforms are fec to controls RP20 RP21 RP22 RP23 and RP24 Parabolic waveforms are developed by IC4 sawtooth processing A positive 4Vpp parabola is present at IC4 8 TP9 and a negat...

Page 40: ...ositioning of the Red Green and Blue CRTs The two signals are the same however trapezoid signals are sent to the Vertical Convergence Amplifier and Keystone signals are sent to the Horizontal Converge...

Page 41: ...Figure 47 Keystone Trapezoid Generator o Figure 48 Side Pincushion Generator...

Page 42: ...r IC1 Vertical Waveform Amplifier IC4 Zero Crossing Detector IC8 and Vertical Horizontal Pulse Generator IC9 The Zero Crossing Detector is driven by three signals a negative sawtooth and a positive pa...

Page 43: ...4 Figure 5 0 Crosshair Generator...

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