Difference in Models

TM 11-5815206-12

113. Difference in Models

Under emergency conditions, the signal lines can be

a. Teletypewriters TT4(*)/TG and TT698(*)/TG

connected directly to terminals 3 and 4 (term. 3

negative) of the line terminal board (A, fig. 26).

are high level and low level signaling units, respec-

tively; they are identical operationally, except that

(8) The TT537/G is designed for operation on

conventional 120- to 130-volt dc signal circuits or for

the TT698(*)/TG operates from an ac source only

whereas the TT4(*)/TG will operate from either an

the reception of 6-volt signals. The TT537/G in-

ac or dc source. The only physical difference of

cludes a solid-state amplification system which in-

significance to the operator are:

creases the low-level signals (6 volts) to the higher

(1) The key tops of the TT4A/TG and

voltage required to operate the selector magnet.

TT-698/TG are round (fig. 19); the key tops of all

( 9 ) The TT-335/TG and the TT537/G are

other models are square (fig. 25).

equipped with casting heaters which maintain the

(2) The dust cover of the TT4A/TG and

equipment at operating temperatures in extremely

TT-698/TG is held to the base with springs and dust

cold weather. The heaters are electrically operated

cover mounting studs (fig. 111); the dust covers of

and are controlled by the operation of a three-position

all other models are held to the base with a C-shaped

LIGHT-HEATER switch (B, fig. 31); an additional

fuse protects the heater circuit. The TT4(*)/TG in-

cam lock on each side of the cover.

cludes a two-position LIGHT switch (A, fig 31).

( 3 ) All models, except the TT4A/TG and

(10) The motors of the TT335/TG and

TT-698/TG, include a blocking plate (fig. 22),

TT537/G are designed for operation with 108- to

which is used to prevent movement of the carriage-

132-volt, 396- to 404-cps alternating current.

return driving gear during shipment. The blocking

(11) The paper storage assembly of the

p l a t e is not included with the TT4A/TG and

TT698/TG.

TT537/G is equipped with retaining levers instead

(4) The location of that portion of the ribbon sen-

of retaining springs to assure positive retention of the

paper roll during transport (fig. 34).

sing level that must be operated manually when

(12) All original TT537/G units included a

removing and replacing the inking ribbon is as

keyboard. However, some units were reworked on

follows:

(a) On all models, except the TT4A/TG and

Work Order No. C9409887 and do not include a

TT698/TG, it is located toward the center of the

keyboard or remote motor control circuitry.

(13) The TT4(*)/TG power cable assembly in-

type-bar carriage, below its associated ribbon cup

(fig. 3-5).

cludes a two-pin connector. The TT335/TG power

cable assembly includes a three-pin, twist-lock con-

(b) On the TT4A/TG and TT698/TG, it is

nector. The TT-537/G power cable assembly includes

located toward the outer side of the type-bar carriage,

a five-pin connector.

below its associated ribbon cup (fig. 19).

(14) The TT-698(*)/TG teletypewriters operate

(5) The TT537/G is provided with platen and

on a line current of less than 100 microampere. Ad-

carriage locks which can be applied and released

without removing the dust cover as shown in figures

ditionally, the high level interface operation, motor

stop function, and dc source input are not included in

23 and 24.

(6) The TT537/G is equipped with automatic

the TT-698(*)/TG teletypewriters.

and

Cases

CY694/PGC1

carriage return and line feed which returns the

(15)

CY694A/PGC1 are identical except that the

carriage to the left margin of the unit, and provides a

single and/or double line feed to prevent overprinting

CY694A/PGC1 includes straps and two wooden

troughs for securing two rolls of recording paper to

when the end of the line is reached.

the lid of the case (fig. 212 and 21), instead of one

(7) On the TT537/G, the power cable is per-

roll as with the CY694/PGC1.

manently wired to the teletypewriter. When the unit

b. T e l e t y p e w r i t e r s T T 7 2 2 ( * ) / T G a n d

is packed to be transported, the power cable is wound

TT-4B,C/TG are identical operationally, except that

around the dust cover and the connector is clamped to

t h e TT722(*)/TG is equipped with automatic

the clamping device on the left front of the dust cover

carriage return and line feed which returns the

before the immersionproof cover is installed (fig.

carriage to the left margin of the unit, and provides a

18). The line cable is shipped loose in a bag (fig.

single and/or double line feed to prevent overprinting

16), and it is plug-connected, through a hole in the

when the end of the line is reached.

dust cover, to the teletypewriter line jack (fig, 18).

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