Audio Outpup Level Verification

Service Adjustments and Calibrations

TC-20G12P / TC-29G12P / TC-29G12PU

REQUIRED EQUIPMENTS / CONNECTIONS:

JIG Filter:	TP18.
RF signal generator:	RF antenna input.
RMS Voltmeter:	Between JIG Filter and GND.
	TP18

PROCEDURE:

1.Apply the next signals on the antenna input: Video: 100 IRE Flat Field, 30% modulation. Audio: 300Hz, 100% modulation, mono

(70±5dB, 75Ω open, P/S 10dB)

2.Check the Audio level to the

RMS Voltmeter show 150 +60_30 mVrms.

MTS CIRCUIT ADJUSTMENT

The MTS Circuit adjust of BR2L chasis, is doing through four steps:

1.VCO Stereo adjustment.

2.Filter adjustment.

3.Input level adjustment.

4.Stereo separation adjustment.

Note: The adjustment must be done in the sequence showed before. VIF, TP12 (Level Detector) must be adjusted before MTS adjustment.

STEP 1 – VCO STEREO ADJUSTMENT

REQUIRED EQUIPMENTS / CONNECTIONS:

1KΩ resistive jumper: Connect between the TP14 and GND.

22µF 16V capacitive jumper: Connect between the TP18 (MPX in). and GND.

Frequency Counter: Connect between the TP22 (R-OUT) and GND.

PROCEDURE:

1.Remove the antenna.

2.On the service mode, select “DAC: M1”

3.Adjust MTS STEREO PLL VCO “DAC: M1” until the frequency counter show 15.734KHz±50Hz. (15.684~15784KHz).

Note: The TV must be turn ON minimum 15 minutes before adjustment.

STEP 2 – FILTER ADJUSTMENT

REQUIRED EQUIPMENTS / CONNECTIONS: RF Generator: Antenna input (RF) Oscilloscope: Between TP21 (L-out) and GND. RMS meter: Between TP18 (MPX-in) and GND.

Note: The GND of oscilloscope must be next of IC2201-01 terminal for minimum noise.

PROCEDURE:

1.Apply the next signal to antenna input ( RF): Video: 100 IRE Flat Field, Modulation 30%. Audio: 15.734KHz sinusoidal wave.

(70±5dB, 75Ω open, P/S 10dB).

2.Adjust the output level signal generator for that a 15.734KHz wave form be 100 ±5mVrms on TP18.

3.On service mode, adjust “DAC: M2”.

4.Adjust MTS filter (DAC:M2) until the wave form amplitude, on oscilloscope screen be minimum.

STEP 3 – INPUT LEVEL ADJUSTMENT

REQUIRED EQUIPMENTS / CONNECTIONS: JIG Filter: Connect to TP22.

RF generator: Connect to RF input antenna terminal.

RMS meter: Between JIG Filter and GND.

TP22

PROCEDURE:

1.Apply the next signal on antenna input ( RF): Video: 100 IRE Flat Field, Modulation 30%. Audio: 300 Hz, modulation 100%, mono. (70±5dB, 75Ω open, P/S 10dB).

2.On service mode, adjust “DAC: M0”

3.Adjust the input level MTS (DAC: M0) until the Voltmeter show 212 ± 10.5mVrms.

STEP 4 – STEREO SEPARATION ADJUSTMENT

REQUIRED EQUIPMENTS / CONNECTIONS: RF generator: Antenna input (RF). Oscilloscope: Between TP22 (R-out) and GND.

PROCEDURE:

1.On audio MENU set STEREO.

2.Apply the next signal on antenna input ( RF): Video: 100 IRE Flat Field, Modulation 30%.

Audio: 300 Hz, modulation 100%, stereo (L channel) (70±5dB, 75Ω open, P/S 10dB).

3.Adjust the low level separation (DAC: M3) until the wave form amplitude on the oscilloscope screen, be minimum.

4.Adjust the audio of RF generator to 3KHz.

5.Adjust the high level separation (DAC: M4) until the wave form amplitude on the oscilloscope screen, be minimum.

6.Repeat steps 2 to 4.

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