Differences in Models - TM-11-5820-518-200015

TM 11-5820-518-20

ARC-51BX, are similar in purpose but are

operation. In addition to these items, the radio

different in appearance and operation.

set relies on aircraft cabling for interconnec-

tions between the radio set control, the re-

a. R a d i o R e c e i v e r - T r a n s m i t t e r s R T - 7 0 2 /

ceiver-transmitter, and the uhf antenna.

ARC-51X

and

RT-742(*)/ARC51BX

differ

a. Primary power source of 27.5 volts 0.5

i n the internal electrical circuitry.

direct current (dc) at 12.25 amperes to power

b. R a d i o R e c e i v e r - T r a n s m i t t e r R T 7 4 2 B /

the radio set.

A R C 5 1 B X only, has provisions for X-mode

b. Uhf transmitting and receiving antenna,

( v o i c e security) operation.

50-ohm input.

c. Headset, 150 ohms, noninductive.

c. T h e C 4 6 7 7 / A R C - 5 1 X t u n e s i n 0 . 1 - m c

i n c r e m e n t s , has a four-numbered frequency

d. Dynamic microphone, 150 ohms, resis-

i n d i c a t o r , and contains a SENS control. The

tive; or a carbon microphone, 82 ohms, resis-

C - 6 2 8 7 / A R C 5 1 B X tunes in 0.05-mc incre-

tive, with a push-to-talk switch.

m e n t s , has a five-numbered frequency indica-

1-15. Differences in Models

t o r , and does not have a SENS control. The

Radio Receiver-Transmitters RT-702/ARC-

C-6287/ARC-51BX

permits

selection

p r e s e t channels and contains a mode selector

51X and RT742(*)/ARC51BX are similiar

w h i c h permits preset channel selection, man-

in purpose, operation, and appearance. Radio

ual channel selection, and automatic switching

Set Control C-4677/ARC-51X, used with the

of the RT742(*)/ARC51BX to the guard

RT-702/ARC-51X, and Radio Set Control C-

c h a n n e l frequency.

6287/ARC-51BX, used with the RT-742(*)/

Figure 1-4. External blower.

Figure 1-5. Reflectometer.

1-5