Mts Adjustment - Panasonic TC-17LA1 Service Manual

TC-17LA1 / TC-20LA1
8.6.

MTS Adjustment

Caution:
MTS adjustment shall be after the aging of 30 minutes or longer.
8.6.1. RF Audio Input level Adjustment
Instrument name
1. Filter jig
2. RF signal generator
3. RMS voltage meter
1. Apply following RF signal at Antenna input.
VIDEO : Flat field, 30 % modulation
AUDIO : 300 Hz, 100 % modulation, monaural
(70 dB ± 5 dB, 75 9, P/S 10 dB)
Note:
Make sure 75 us PRE-EMPHASIS is off.
2. Adjust "MTSIN" data (Input level) until the RMS voltage meter indicates 106 mVrms ± 6 mVrms
8.6.2. Stereo Separation Adjustment
Instrument name
1. RF signal generator
2. Oscilloscope
3. Headphone jig
1. Select STEREO mode in the AUDIO Menu.
2. Set "Audio volume" DAC to "40".
3. Apply following RF signal at Antenna input.
VIDEO : Flat field, 30% modulation
AUDIO : 300Hz, 30% modulation, STEREO (LEFT only)
(70dB ± 5dB, 75 9 OPEN, P/S 10dB)
Note:
After setting 30% modulation with PL SW and NR SW off, turn PL SW and NR SW on.
4. Adjust "SEPAL" data (Low-level separation) until the amplitude.
5. Apply following RF signal at Antenna input.
VIDEO : Flat field, 30% modulation
AUDIO : 3kHz, 30% modulation, STEREO (LEFT only)
(70dB ± 5dB, 759 OPEN, P/S 10dB)
Note:
After setting 30% modulation with PL SW and NR SW off, turn PL SW and NR SW on.
6. Adjust "SEPAH" data (High-level separation) until the amplitude of the waveform on the oscilloscope is minimum.
7. Repeat steps 3. to 6. until Low-level separation and High-level separation satisfy above-mentioned conditions.
Note:
The separation must be more than 20 dB at 300Hz and 3kHz.
Connection
TPA180 - GND (TP181)
RF ANT. INPUT
Filter jig
Connection
RF ANT. INPUT
TPA150 - GND (TP181)
24
Remarks
Filter jig
Remarks
Headphone jig