Sony TC-766-2 Service Manual page 9

TC-766-2
Pinch Roller Pressure Check
— playback mode —
1.~ Place the dial-cord ring between the pinch
roller and pinch-roller cap.
pinch-roller cap
pinch roller
dial cord (0.5mm dia.)
In playback mode, pull the spring scale on the
center line made by the centers of the capstan
and pinch roller.
Slowly return the pinch roller and read the
spring scale just when the pinch roller starts to
rotate.
capstans
pinch roller
ly X\
y spring scale
spring scale Ng
:
(1 lb 120z—2 lb 10 oz) \
Pull.
pressure difference
between the take-up
and supply sides:
within 200g (7 oz}
Forward Torque Adjustment
; hub for measurement
Remove the side board (right).
Apply the rated ac voltage to the AC IN.
Set the TAPE SPEED switch to 19cm/s and
REEL SIZE switch to 10%.
; @)
In playback mode, adjust RV703 for the — @)
specified torques. (@3] RV703
Set REEL SIZE switch to 7 and check torques.
torque meter
Set the tension
REEL SIZE switch
ice
arm to ON position
using a rubber band
10% 7 etc.
REEL SIZE switch
520-580 g-cm 260—320 g:cm
(7.3-8.0 oz-inch) | (3.7—4.4 0z-inch})
—13-