Mechanical Adjustments; Pinch Roller Pressure Adjustment; Reel Base Torque Adjustment - Pioneer CT-730 Service Manual

12. ADJUSTMENTS
12.1 MECHANICAL ADJUSTMENTS
Prior to starting mechanical adjustments, clean
the capstan, pinch roller, idler and belt with an
alcohol moistened swab.
12.1.1 Pinch Roller Pressure Adjustment
1. Put the tape deck into playback mode without
Ioading a cassette half.
2. Gently push against the pinch roller arm with
a tension gauge (service part no. GGK-047) and
separate the pinch roller
slightly from the
capstan. (See Fig. 12-1).
3. Then ease the pinch roller back onto the cap-
stan, and read the value when the pinch roller
starts to rotate. If the reading fails to lie
between 2OOg and 3509, replace the pinch
pressure spring (part no. RBH-893).
Tension gauge
(Part No. CGK-0471
Capstan
Pin ch ro ller
Pinch roll er arm
Pinch pressure spring
( P ar t No . RB H- 8 9 3)
Fig. 12-1 Pinch roller pressure adjustment
12.1.2 Reel Base Torque Adjustment
Measure the reel base torque during playback,
fast forward and rewind modes with a cassette type
torque meter (service part no. GGK-056). The
measured values should lie within the ranges listed
below in Table 1. If the measured values lie outside
these ranges, replace the supply reel assembly (pa*
no. RXB-377), take-up reel assembly (part no.
RXB-360) or the full drive arm assembly (part
no. RXB-376).
Table 1
TU reel base ass'y Supply reel base ass'y
Playback mode
35 - 55g.cm
2 - S g . c m
Farst forward mode
75 - 11Og.cm
2 - S g . c m
R e w i n d m o d e
* 2 - S g . c m 75 - 110g.cm
NOTE:
* denotes bach tension torque.
3 7
12.1.3 Tape Speed Adjustment
1. Connect a frequency counter to the PLAY
terminals.
2. Play the Skllz portion of the STD-301 test
tape. At the beginning of the tape, the fre-
quency should lie between 3000H2 and 3010
Hz, arrd may be adjusted by turning the varia-
ble resistor located in the capstan motor
adjustment hole shown in Fig. I2-2. Turning
clockwise increases tape speed, while turning
counterclockwise decreases the speed.
Tape speed increased
Tape speed decreased
Q screwdr:iver
Fig. 12-2 Tape speed adjustment
12.1.4
REC Detector Switch Adjustment
1. Prepare a cassette half with the erasure pre-
vention tabs intact, and one with the tabs
broken off.
2. Adjust the record prevention lever (shown by
the arrow in Fig. 12-3) by bending so that the
lever switch is on when a half without tabs is
loaded, and off when a half with tabs is loaded.
Side plate L assembly
Lever switch
( R EC detect or
switch)
Capstan motor
Fig. 12-3 REC detector switch adjustment