Kenwood KVT-910DVD Service Manual page 50

KVT-910DVD/920DVD/930DVD/
940DVD/960DVD
X86 Circuit Adjustment Specification (M, X, C type)
Item
1. Adjustment of image
detection coil
L103
2. Adjustment of audio
detection coi
L101
3. S-METER
adjustment
VR102
4. RF AGC adjustment
VR101
5. Duversuty free-run
frequency
VR1
52
ADJUSTMENT
Adjustment Method & Value
1. Turn VR101 [RF-AGC] counter-clockwise as much as
possible.
2. Impress DC2.0V to TP [IF AGC] (#36 of IC101).
3. Input fo=38.0MHz Mod=1kHz AM60% Level=100dBµ toTP
[IF] (#1 of CF1).
4. Observe the waveform of TP [VIDEO] (#8 of IC101) with an
oscilloscope and adjust L103 so that output level will be the
maximum.
1. Turn VR101 [RF-AGC] counter-clockwise as much as
possible.
2. Input fo=31.5MHz non-modulated Level=94dBµ to TP [IF]
(#1 of CF1).
3. Connect voltmeter to TP [SIF] (both ends of R107) and
adjust L101 so that 0V ± 0.01V is achieved.
1. Turn VR101 [RF-AGC] clockwise as much as possible.
2. Input RF signal 30dBµ CHINA 9CH color bar to the ANT
input terminal.
3. Audio (P/S ratio-6dB) non-modulated
4. Adjust VR102 [SMET] to 3.5V ± 0.05V, by connecting a
voltmeter to CN5.
5. Set RF signal to 70dBµ and adjust VR101 [RF-AGC] so
that the value of the voltmeter connected to CN3 is 4.8V ±
0.05V.
1. Connect a frequency counter to PIN 1 of CN5 [#7 of IC2].
2. Connect Pin 3 of CN5 [#8 of IC2] and PIN2 [GND].
3. Adjust VR1 [15kHz] and set to 15625Hz ± 100Hz
• ANT non-signal
• If the waveform is
clipped, raise DC
voltage somewhat.
• AC range
Maximu
• ANT non-signal
• Slide VR5 so that
AGC will not be
effective at 30dBµ.
• Be sure to adjust S-
METER before
adjusting RFAGC.
• ANT non-signal
Condition