Panasonic TC-23LX60 Service Manual

Also see for TC23LX60 - 23" LCD TV: Operating instructions Operating instructions Operating instructions manual Operating instructions Manual de instrucciones

Contents

Panasonic TC-23LX60 Service Manual Manual pdf 14 page image

11 MTS circuit adjustmentThe MTS circuit adjustment require two steps:1. Input level adjustment.2. Stereo separation adjustment.Input level adjustmentService DAC adjustment (MTSIN)PREPARATION1. Connect an RMS meter with filter jig as shown in figureto TP1105 or TP1107 and gound.2. Connect an RF sigal generator to the RF antenna Input.PROCEDURE1. Apply the following signal from the RF signal generator.• Video: flat field, 30% modulation (70±5dB, 75 ohmOPEN, P/S 10dB).• Audio: 300Hz, 100% modulation, monaural(70±5dB, 75 ohm OPEN, P/S 10dB.) Make sure thatthe 75μs pre-emphasis is OFF.2. Adjust the MTS input level adjustment ìMTSINî datauntil the RMS voltage measured is 106mVrms ±6.0mVrms.Stereo separation adjustment (SEPAH)PREPARATION1. Connect an R.F. signal generator to the RF antennainput.2. Connect a scope to TP1104 or TP1106 and ground.PROCEDURE1. Select stereo mode in audio menu.2. Apply the following signal from the RF signal generator.• Video: flat field, 30% modulation.• Audio: 300Hz, 30% modulation, stereo (left only)(70±5dB, 75 ohm OPEN, P/S 10dB.)Note: After setting 30% modulation with P.L. SWand N.R. SW OFF, turn P.L. SW and N.R. SW ON.3. In service mode, adjust the MTS Low-Level separationadjustment ìSEPALî data until the amplitude displayedon the scope is minimum.4. Apply the following signal from the RF signal generator.• Video: flat field, 30% modulation.• Audio: 300Hz, 30% modulation, stereo (left only)(70±5dB, 75 ohm OPEN, P/S 10dB.)Note: After setting 30% modulation with P.L. SWand N.R. SW OFF, turn P.L. SW and N.R. SW ON.5. Adjust the MTS High-level separation adjustmentìSEPAHî until the amplitude displayed on the scope isminimum.6. Repeat above steps 2 through 5 until the amplitude is atminimum for both signals.14