Sharp VC-A30G Serviceanleitung Seite 39

m@ ADJUSTMENT OF THE IF CIRCUIT
(ONLY FOR VC-A30S, SM, QM, SV)
Adjustment of the RF AGC
Measuring Oscilloscope
instrument
Signal generator
Input signal Colour bar signal
Test point TP1551 (GND)
TP1552 (Video Output)
Adjusting point VRO01 (AGC control)
1. Receive the colour bar signal (input field
strength: 80 dBy).
2. Observe the video output terminal waveform on
the oscilloscope. Adjust VRO01 (AGC control) in
the IF pack until the noise disappears from the
oscilloscope screen and the waveform nearly
comes into sync.
Just before shrinking
Figure 2-13.
39
VC-A30G(BR) VC-A30S(BR) ;
VC-A30GM(BR) VC-A30SM(BR)
VC-A300M(BR) VC-A30SV(BR)
Adjustment of the AFT
Measuring Oscilloscope
instrument
Signal generator
Input signal PIF frequency uniwave
Colour bar signal (70 dBy)
Test point TP1551 (GND)
TP1552 (Video Output)
Adjusting point T002 (AFT coil)
Specification
*PIF Frequency
S,N, NZ, E, B, LM, 38.9MHz
SV, SM, QM
H, HM, W, K 39.5MHz
RF AGC
IF Module