sary to increase or decrease the value of
to turn since it is being moved in and out of
R34 to obtain the normal operating cur-
the clamp The direction of the image, therefore,
rent of 75 to 85 ma in the synchronous
must be restored to its original position.
motor. Before changing any resistor,
f. Recorder Optical System, Parts Description
see that the tubes involved are not de-
fective and that the resistance of other
--
resistora in the circuit is correct. Trans-
Ref
Function
Name of part and description
symbol
former T1 is a class B driver transformer
--
----.
and may be replaced with any similar
Recorder optical sys-
RECORDER L A M P
transformer that will fit. When making
tem.
ASSEMBLY.
a replacement, try reversing the direction
Converte signal light.
A
LAMP, recorder ---------
of current through the primary winding
S C R E W : 3/8 N o . 6 - 3 2 .
Fastens pressure plate.
B
to obtain the maximum current in the
Clamps lamp base
PLATE, pressure --------
C
sleeve.
motor circuit.
D
Clamps recorder lamp
SLEEVE, lamp base --------
(2) Facsimile Transceivers TT-1B/TXC-1
in place.
through TT-1F/TXC-1. These models
E
LENS, objective: double
Focuses light passing
have control R93, in the input circuit of
convex; Hasting Trip-
through aperture
adjust the motor
V4, which is used
onto drum.
let 10x.
F
Protects recorder
RING, rubber ---------
current to 90 ma as indicated on meter
lamp.
M2. Another control, R97, is located
Adjusts lens barrel.
RING, knurled ----------
G
in the cathode circuit of V13 so that bias
BARREL SUBASSEM-
Mounts and shields
H
may be adjusted for best direct record-
BLY: lens.
objective lens.
ing results without changing the value
I
Locknut.
L O C K N U T ------------
LENS, condensing: piano
J
Field lens (eee note).
of R67.
convex: 18-mm focal
b. Output Stage, V5 and V6. Flashovers may
length.
occur in the sockets of V5 and V6. Do not scrape
K
PLATE, aperture: for
Light aperture.
away the carbonized portion of the sockets. Re-
AN/TXC-1.
place them with new ones. If the plate circuit
L
SupPorte lamp hous-
CLAMP, lamp recorder:
ing.
zinc diecast.
becomes shorted to ground either through the
M
BLOCK, raising ---- ----
Raises optical support.
socket, wiring, or tubes, the motor of Facsimile
N
Prevents vibration of
SNUBBER ------------
Transceiver TT1/TXC-1 will burn out if the
lens barrel.
power is left on for more than a few seconds.
Motors of Facsimile Transceivers TT-1A/TXC-1
Note. In Facsimile Transceiver TT-1C/TXC-1, TT-
through TT-1F/TXC-1 are protected by fuses.
1D/TXC-1,
TT-1E/TXC-1,
and
TT-1F/TXC-1,
this
In Facsimile Transceiver TT-1F/TXC-1, capaci-
lens is omitted, since it is not necessary for proper opera-
tor C69 has been added as a plate bypass capacitor
tion.
to reduce the high peak voltages on motor ampli-
fier tubes V5 and V6 in the 1,800-cycle (60RPM)
a. Motor Amplifier Driver V4. Facsimile Trans-
position of the speed switch. This reduces arcing
in the tubes and flashovers in the sockets.
ceivers TT-1C/TXC-1 and TT1A/TXC-1 differ
Caution: Under normal operating conditions}
from Facsimile Transceivers TT-1B/TXC-1
the ac voltage across choke T6 is approximately
through TT-1F/TXC-1 in the grid and cathode
800 volts. Be careful when testing the circuit
circuits of V4. MWO SIG 11-2258-2 modifies
with the power on.
the 1 and 1A models to make these circuits the
same as in the later models.
c. Filter. A high-voltage leak in choke T6 or
(1) Facsimile Transceivers TT-1/TXC-1 and
in capacitor C28 or C29 may not interfere with
TT-1A/TXC-1. In these two trans-
the operation of the synchronous motor, but will
cause disturbances in nearby radio-reoeiving equip-
ceivers, the cathode bias for V4 is de-
veloped across resistors R66 and R67 and
ment. In such cases, replace the choke or capaci-
the phase magnet coil. The resistors are
tor. A short to ground in this circuit will cause
the synchronous motor or fuse to burn out.
associated with V13. The value
may be altered to improve the direct re-
d. MOTOR JACK.. The input circuit includes
MOTOR JACK J6 which may develop contact
cording. If this is done, it may be neces-
