Studer J37 - Page 20

Bremsmomenl
FORCE
OF BRAKE
2OOOcmg
46)
;)
Fig.7
The STUDER
J-37
Magnetic Tape
Recorder has three independent
brake systems. Durlng normal
operatlon, the braking
(
back tension
)
ls
purely
electrical,
by
means
of
a suitable
torque
of the
take-off motor. The magnltude of thls
torque ls controlled by the tape
tenslon balance via
a mag-
netic amplifier. As thls
ensures constant tape tension throughout
the reel. its
absolute value can
be held low, thereby reduclng
wear on tapes
and
heads.
The mechanical brakes
serve only for
holdlng
the
turntables when the machine
ls stopped. The brake bands
are made of
stalnless steel.
The brake lining
is
made
of woven nylon which malntalns
its characteristics over long
periods
of
tlme. The wear is very
slight because the brakes only
provide
a very
small
braking torque.
Brake
tension ls
adjusted
with no
power
to
the spooling motors:
1. Remove turntable
and
underlylng
dust cover. You will
see
now
the brake faclllties
as shown Lnf.lg. 7.
Z,
Insert
NAB
adapter ard
place
a NAB ReeI with
a
few feet
of tape on the
adapter
shaft.
3. Attach a
spring
scale to the
end of the tape.