supplied with Facsimile Set AN/TXC-1D. This
be diverted to ground. It is therefore not neces-
switch is located on the blower and canister sup-
sary for the operator to be with the equipment
porting bracket (fig. 2) and should be thrown to
at the end of a transmission.
the ON position only when the equipment is used
d. Blower Switch (S9). A toggle ON-OFF
for direct recording.
switch is provided for the dust removal blower
Section Ill. OPERATION UNDER USUAL CONDITIONS
Note. The operating instructions in this section are based on the use of a voice communication circuit between
transmitting and receiving operators. Blind circuits, however, in which transmission and reception of facsimile copy are
completed on prearranged schedules, are feasible without voice communication. Experienced operators will find numerous
satisfactory ways of saving time by varying the operating procedures described in this section.
Satisfactory operation may be obtained even
23. Preparations
though the indexes of cooperation are not exactly
Before operating Facsimile Set AN/TXC-1(*),
determine the type of circuit being used, wire or
the same. Differences of as much as 5 or 10 per-
radio, and all types of transmission and reception
cent are generally not noticeable in photographic
desired; this will affect the operating procedure.
or message copy. The indexes of cooperation
a. Index of Cooperation. Transmitting and
may differ by as much as 50 percent for weather
receiving equipments at each end of the circuit
map work or other line illustrations without
should have the same index of cooperation, the
affecting the usability of the received copy. The
same speed, and a recording system responsive to
maximum speed tolerance between the trans-
the modulated signal of the transmitter. The
mitting and receiving scanning drums of Facsimile
index of cooperation is equal to the scanning drum
Transceivers TT-1(*)/TXC-1 is .00033 percent.
diameter times the pitch (lines per inch scanned);
The table below lists the standards applicable in
thus, the index of cooperation of Facsimile
present day military and commercial wire and
Transceiver TT-1(*)/TXC-1 is equal to 6 (drum
diameter in inches) 96 (lines per inch) = 576.
radiophoto facsimile circuits.
