Video And Reference Signal System Adjustment; 27 Mhz Vco Free-Run Adjustment; Clock (74 Mhz) Duty Adjustment - Sony HDCU3300 Maintenance Manual

3-3. Video and Reference Signal System
Adjustment

3-3-1. 27 MHz VCO Free-run Adjustment

Measure : Frequency counter, Oscilloscope
Preparation
. To be extended : AT-167S board (front side)
. Remove the cable connected to the REFERENCE IN
connector on the HDCU rear panel.
. S401 (REFERENCE)/AT-167S board panel side → SD
. Connect the measure as shown in the following figure.
. After turning on the power, wait for 10 minutes at least
and start adjustment.
CH2
Probe
IN
Oscilloscope
Adjustment Procedure
Measuring point : TP704 (F-4)/AT-167S board
Adjusting point : 1RV701 (F-2)/AT-167S board
27,000,000 ± 10 Hz
Specifications :
Setting after Adjustment
After finishing the adjustment, return the switches to the
original configuration. Reconnect the disconnected cables.
3-6 (E)
CH2 IN
OUT
Frequency
counter

3-3-2. Clock (74 MHz) Duty Adjustment

Measure : Oscilloscope (20 MHz BWLimit: ON)
Adjustment Procedure
Measuring point : TP714 (H-1)/AT-167S board
Adjusting point : 1RV702 (G-1)/AT-167S board
C = 1.60 ± 0.04 Vdc
Specifications :
A
A=B
B
TP701
TP714
1
RV702
RV701 1
S410
S412
S405
S413
S404
S416
S403
S401
AT-167S board (A side and panel side)
C
GND
TP601 TP601
S104 S102
S103 S101
S420
S402
HDCU3300/MM (J,E)