JVC RC-828L Service Manual page 11

FUNCTION Switch : TAPE
Mode Switches
Center Position
(except
Biphonic
Processor Alignment)
Note:
1. Align in numerical order.
2. When changing
the
play/record
head
align all
items from 1. to 5.
3. Set the slider of semi-fixed variable resistors to
the center position, when replacing them, before
aligning.
1. Azimuth Alignment
a. Connect a dual channel oscilloscope to the output
terminals of DIN socket.
b. Playback the reference tape (10kHz, 25mM/mm,
—15dB).
c. Adjust the head azimuth so that the output signals of
left and right channels become maximum and in
phase.
Note: If the head cover is removed, the azimuth align-
ment can be done though the mechanism has
been mounted in the cabinet. As for removing
the head cover, refer to page 7.
2. Playback Level Alignment
a. Connect a V.T.V.M. to the output terminals of DIN
socket. .
b. Playback the reference tape (1kHz, 16mM/mm).
c. Adjust R168 (left channel) and R268 (right channel)
so that the output becomes 0.6V.
3. Recording Level Alignment
a. Remove the solder on the part (A) of copper side to
open circuit as shown in Fig. 28.
b. Set the TAPE switch to NORMAL, REC switch to
MANUAL and REC LEVEL controls to MAX. in the
recording mode.
c. Connect the V.T.V.M. across R108 (left) and R208
(right).
Fig. 28
| RC-828L/LB
d. Supply the signal (1kHz, -60dBs) to the input
terminals of DIN socket.
Note: Do not supply the signal to both channels at
once.
e. Adjust R131 (left) and R231 (right) so that the
voltage becomes 0.7mV (70QuA/10Q).
. Level Meter Alignment
d. Solder the part (A).
. Bias Alignment
. Biphonic Processor Alignment
— Left Output
Left Input
Right Input
Left Output
Fig. 29
No. 1344