Panasonic TC-14B10P, Service Manual

- 9 -

TC-14B10P / TC-20B10P

Service Adjustments and Calibrations

3-

ADJUSTMENTS

3.1- Adjust AFT using coil L167 until  the voltage below

(*) is obtained at TPE29.

(*)  4,0±1,0V (after 10 seconds “ON”)

(*)  4.5±1,0V (after heating)

3.2- Vary the frequency of CW oscillator between

±100KHz and verify if tension variation at the

multimeter is higher than ±1,2V

AGC-RF ADJUSTMENTS

1-

REQUIRED EQUIPMENT

1.1- Digital Multimeter

1.2- Attenuator

2-

PREPARATION

2.1- Tune a COLORBAR patten.

2.2- Adjust the input signal level to 64±2dB ( 75

Ω

 open).

2.3- Connect Digital multimeter between TPE23 and

ground

3-

ADJUSTMENTS

3.1- Select DAC AGC RF(RF) CHQ4 (Service Mode)

3.2- Adjust the DAC using the keys VOL(+) and VOL(_)

until  ±6,2V at TPE23.

NOISE LEVEL ADJUSTMENTS

1-

REQUIRED EQUIPMENTS

1.1- Oscilloscope

1.2- 7KHz filter

2-

PREPARATION

2.1- Tune a COLORBAR patten (no sound modulation).

2.2- Position tone control to center

2.3- Position VOLUME control to maximum.

2.4- Connect Oscilloscope to speakers terminals.

3-

VERIFICATION

3.1- The maximum amplitude  of the noise signal should

be less than 1,5Vp-p.

3.2- When it is higher than 1,5Vp-p,  activate 7KHz filter

at the speakers terminals and verify if noise level is

less than 0,5Vp-p.

Oscilloscope

1,5Vp-p

CALIBRATION OF VIDEO IF

 ( continuing)

1-

PREPARATION

2.1- Connect the VIF generator positive output cable to

TPE33 and the negative to ground.

2.2- Connect the VIF detector positive output cable to TPE13

and negative to ground.

2.3- Connect the +9V power source positive to pin 3 of IC851

and negative to ground.

2.4- Connect the +4V power source positive in series with

1K

Ω 

resistor to pin 63 of IC601 and negative to ground.

2.5- Connect the polarization of AGC with positive to TPE21

(IF AGC) and negative to the ground.

2.6- Enter Serviceman Mode.

2-

ADJUSTMENTS

3.1- Calibrate monitor to 200mVp-p

3.2- Decrease the VIF generator output to minimum signal.

3.3- First, turn on the instruments and after that, the power

sources.

3.4- Adjust bias AGC to obtain maximum gain.

3.5- Adjust the VIF generator output to obtain 200mVp-p at

the monitor.

3.6- Increase 20dB to VIF generator output and adjust the

Bias AGC to obtain 200mVp-p at the monitor

3.7- Confirm that the level of CC (42,17 MHz) and PC (

45,75 MHz) are within the especificated below.

AFT ADJUSTMENTS

1-

REQUIRED EQUIPMENTS

1.1- Oscilator CW 45,75 MHz

1.2- VIF detector

1.3- Digital multimeter

1.4- Short Jumper

2-

PREPARATION

2.1- Disconnect the signal from the antenna terminal

2.2- Connect the multimeter between TPE29 and ground

2.3- Connect the CW oscilator using VIF detector

between TPE33 and ground

2.4- Adjust the CW oscilator output to 90+-5dBu

(75

Ω

 open).

2.5- Position the DAC AFT in “80H”.

200m Vp-p

39,75 41,25

47,25

41,65

CC     42,17

45 ± 15%

PC     45,75

45 ± 15%

42,75

45,00

ZERO BEAT

↓

ENGLISH