Text preview for : Audio_Adjustments.pdf part of Mitsubishi VS-50805, WT-60805, WS-55905, WS-65905, WS-73905, WS-55805, WT-46805 Mitsubishi VS-50805, WT-60805, WS-55905, WS-65905, WS-73905, WS-55805, WT-46805 (Chassis V16 N W) (Training Manual + Schematic)



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MODELS: VS-50805 / VS-60805 / WT-46805 / WS-55805 / WS-55905 / WS-65905 / WS-73905
[Audio Circuit] 1. MCS Input Level
Measuring Instrument Test Point Ext. Trigger Measuring Range Input Signal Input Terminal Oscilloscope TP14A, TP15A, TP14B, TP15B -----50mV/Div RF Monaural 400 Hz modulation RF Input

Purpose:

Check the input signal level to the MCS circuit

Symptom: Distorted sound during a stereo broadcast.
1. Supply an RF monaural signal to the Ant A input, 400 Hz at 100% modulation (25 kHz deviation). 2. Connect the oscilloscope to TP14A (Main Tuner Left Audio). 3. Enter the Adjustment Mode and select the Audio Function. 4. Verify that the Audio Function items are set to the data values given the table below. 5. Confirm the audio level at TP14A is 1.1 Vp-p 0.1V. 6. Connect the oscilloscope to TP15A (Main Tuner Right Audio). 7. Confirm that the audio level at TP15A is 1.1 Vp-p 0.1V. 8. Connect the oscilloscope to TP14B (Sub Tuner Left Audio). 9. Confirm that the audio level at TP14B is 1.1 Vp-p 0.1V. 10. Connect the oscilloscope to TP15B (Sub Tuner Right Audio). 11. Confirm that the audio level at TP15B is 1.1 Vp-p 0.1V. Note: Adjustment 2 (Stereo Separation) must be performed after this adjustment)

SERVICE MODE Activate .. MENU-1-2-5-7 Function .....AUDIO Item No. ..VIDEO Adjust Data ..ADJUST Save Data . ENTER Exit ..MENU (twice)

AUDIO FUNCTION Item # Abbrev. 1 AGC 2 MON 3 SUR 4 VMX

Data 0 8 8 8

[Audio Circuit] 2. Separation
Measuring Instrument Test Point Ext. Trigger Measuring Range Input Signal Input Terminal Oscilloscope TP14A, TP15A TP14B, TP15B -----10mV/Div RF Stereo RF Input

Purpose

Check stereo separation

Symptom: Poor stereo separation

Note: This adjustment must follow Adjustment 1 (Input Level) 1. Supply a RF Stereo Signal (dual tone stereo) to the Ant. A input. Left Channel = 300 Hz modulation Right Channel = 3 kHz modulation 2. Connect the oscilloscope to TP14A (Main Tuner Left Audio). 3. Enter the Service Mode and select the Audio Function. 4. Set the data values to those given in the table below. 5. Confirm the presence of 300 Hz signal at: TP14A (Main Tuner Left Audio) TP14B (Sub tuner Left Audio) 6. Confirm the presence of 3 kHz signal at: TP15A (Main Tuner Right Audio) TP15B (Sub Tuner Right Audio) .

SERVICE MODE Activate .. MENU-1-2-5-7 Function .....AUDIO Item No. ..VIDEO Adjust Data ..ADJUST Save Data . ENTER Exit ..MENU (twice)

AUDIO FUNCTION Item # Abbrev. 1 AGC 2 MON 3 SUR 4 VMX

Data 0 8 8 8

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