Read Sony FDL-PT22 / FDL-PT22JE Service Manual online
– 9 –
RF.AGC ADJUSTMENT
(1) Input the VHF color bar signal from the test signal generator.
(2) Adjust RV201 to optimum position so that there is no snow
noise on the screen.
CHANNEL DISPLAY POSITION ADJUSTMENT
(1) Set S601 in the VHF position.
Insert resistors (47k
Ω
+ 15k
Ω
) between JL25 and JL77 (4.5V
line), and short circuit JL21 and JL30 (D.GND).
(2) Receive 2ch, and adjust the channel display position with
RV002.
(3) Receive 13ch, and adjust the display bar with RV004.
(4) Carry out tracking, because (2) and (3) interfere with each other.
(5) Receive 6 and 7ch, and check that the display bar conforms to
the standard.
(6) Set S601 in the UHF position.
(7) Receive 14ch and adjust the display position with RV001.
(8) Receive 40ch and 69ch, and check that the display bar con-
forms to the standard.
(9) Remove resistors from JL25 and JL77, and open the short cir-
cuit between JL21 and JL30
Approx. 1.0Vp
45.75MHz
Fig.3-2
(3) Remove the external voltage (MGC) from JL51.
(4) Connect the output between JL31 (AFT) and JL30 (D.GND) to
an oscilloscope, and roughly adjust T201 so that the position
of 45.75MHz will be a zero cross.
(5) Remove 1k
Ω
from the section between JL77 (4.5V) and JL28
(RF AGC).
AFT ADJUSTMENT
(1) Insert 1k
Ω
between JL77 (4.5V) and JL28 (RF AGC).
Note:
Because of drifting due to aging, adjustment should
be made at the end of the process.
be made at the end of the process.
(2) Switch the sweep signal to CW.
fo = 45.75MHz
±
5kHz
Input the above signal to the section between JL26 (IF) and
JL27 (IF GND), and finely adjust T201 so that the level be-
tween JL31 (AFT) and JL30 (D.GND) will be 2.2
±
0.4VDC.
(3) Remove 1k
Ω
from the section between JL77 (4.5V) and JL28
(RF AGC).
Display bar
Channel No.
6
JL77
JL25
47K
15K
*Channel No. and display ber are to be in line.
Fig.3-3
Click on the first or last page to see other FDL-PT22 / FDL-PT22JE service manuals if exist.