14AG2-SMK3-A
[2] ADJUSTMENT POINT
1. PIF ADJUSTMENT CHECKING
No.Adjustment pointAdjustment procedure/conditionsWaveform and others
1Tuner IFT1. Get the tuner ready to receive the CH. E - 9
( PRESET )signal, but with no signal input.
Adjust the PLL data.
2. Connect the sweep generator's output cable to
10k1n601000p
the tuner antenna. ( RF SWEEP )
3. Adjust the sweep generator's to 80dB?V.OscilloscopeIFOUT
4. Connect the response lead ( use LOW IMPED-100k1000p 75ohm
ANCE probe with wave detector ; see Fig.1 ) to
the tuner's IF output terminal. ( This terminal mustFig.1
have the probe alone connected ).
E-9 CH
5. Set the RF AGC to 0 - 6 V with no saturation with
the waveform.
6. Adjust the tuner IF coil to obtain the waveform asPC
showninFig.2.
-1.5+/-0.8dB
Note: Be sure to keep the tuner cover in posi-Fig.2
tion during this adjustment.
2RF-AGC1. Receive "PAL COLOUR BAR" signal.* for Auto ADJ
TAKE OVER?SignalStrength:56?1dB?V(75ohmopen)1)Receive PAL COLOUR BAR
POINT AD-signal.
JUSTMENT2. Connect the oscilloscope to TP201 (Tuner?s AGCsignal strength: 56 ? 1dB?V(75
2
(IC BUSTerminal) as shown in Fig. 3-1.ohm open)
CONTROL)1)Go to service mode.
Oscilloscope
2)Go to service data V01, press
+TP201
(AUTO &R/C to operate auto key (Hex
0.1V
MANUAL ADJ)?C1) and confirm the ŹOK
display on the screen.
Bias boxTV Set
3)If appear NG, increase data
+
some step and pls repeat step2.
4)Proceed step 4 & 5 in manual
?
mode.
? Bias box: About 4.5 V
Fig. 3-1
3. Call "V01" mode in service mode. Adjust the "V01"
bus data to obtain the Tuner output pin drop
0.1~1.0V below maximum voltage.
4. Change the antenna input signal to 63~67dB?V,
and make sure there is no noise.
5. Turn up the input signal to 90~95 dB?Vtobesure
that there is no cross modulation beat.
3 - 13 |
ACEC
