Sony MHC-6800 Service Manual page 51

3. Playback Mode
test tape
P-4-A100
(0kHz, —10dB)
oscilloscope
LcH 47ka
set
R-CH
LINE OUT (CNJ401)
OOO SO
in phase 45° = 90" 135° 180
good wrong
4. Change the reverse playback mode and repeat the steps
1 to 3.
5. After the adjustment, lock the adjustment screw with
suitable locking compound
Adjustment Location : —record/playback head—
azimuth cover
Removing the azimuth cover.
Unlock the stoppers of the azimuth cover
using a L-shaped wrench in order to adjust
Tape Speed Adjustment | DECK A DECK B
Procedure:
—Forward Playback Mode—
test tape
WS.48B
(3kHz, 0dB)
frequency counter
LINE OUT (CNJ401)
Perform high speed adjustment before normal speed adjust-
ment.
(High speed adjustment)
1. Short TP601 (TC main board) when the power is OFF.
2. Turn on the power and put the deck A into the FWD
mode.
3. Push the DUBBING MODE switch and set display to
HIGH. (The set enters into high speed playback mode.)
4, Adjust RV72A (H) of the deck A so that a reading of the
frequency counter meets the adjustment value.
5. Adjust the RV72B (H) of deck B performing steps 2 to 5
as deck A.
(Normal speed adjustment)
1. Put the set into the FWD playback mode.
2. At this time, adjust RV71A (L) of the deck A and RV71B
(L) of the deck B so that a reading of the frequency
counter meets the adjustment value.
Adjustment Limits :
Speed Frequency Counter Reading
ie High = 6,000 = 30Hz
Normal 3,000 + 15Hz
Frequency difference between the beginning and the end of
the tape should be within 3%.
Frequency difference between deck A and deck B the begin-
ning of the tape should be within 1%.
Adjustment Location: MD-A board
MD-B HX PRO board