Transmit Path-continued

TM 11-5820-695-35

level signal is also routed to the metering circuits in

assembly 1A13. The direct current portion of the input

1A15A8 through alarm monitor 1A5.

signal is looped back to the TO CABLE output of T-

1064/GRC-144 by way of the cable-to-radio and the

(4) The combined pcm and ow signal

radio-to-cable circuits of 1A12 (para 22a(1)).

frequency modulates a 150 MHz carrier in 1A8.

Electronic frequency control 1A7 provides automatic

(2) The thru ow rec signal is amplified

frequency control (afc) of the 150 MHz carrier.

in orderwire assembly 1A13 and distributed to Handset

Frequency control and modulator signal levels from 1A7

H-156/U, Telephone Set TA-12/PT, attenuator assembly

and 1A8 are applied to the metering circuits in 1A15AB.

1A3 (to radio ow), and to the loudspeaker on 1A15A8.

The 150 MHz frequency modulated output of 1A8 is

The loudspeaker level is controlled by the SPEAKER

applied to transmitter frequency mixer stage 1A9 where

VOLUME control. The RING pushbutton on 1A15A8

it is mixed with a 4.55 to 4.856 GHz local oscillator

provides in-band tone signaling to locally initiate ow

signal which is produced by electrical frequency

communications. The RING indicator on 1A15A8 lights

synthesizer 1A14 and a times 16 multiplier chain. The

amber when the RING pushbutton is depressed or when

electrical frequency synthesizer generates a highly

a ring signal is received from a remote ow station. The

stable frequency in the range of 284.375 to 308.125

CNTRL ALARM indicator on meter panel assembly

MHz. The detected output level (synth level) is applied

1A15A8 is controlled by alarm circuits in 1A13.

to metering circuits on 1A15A8. The SYNTH OVEN

Normally, the CNTRL ALARM indicator is lighted green.

lamp (press-to test) on meter panel assembly 1A15A8

If an alarm condition (pcm aim, transmitter aim, receiver

lights white when the standard radio frequency oscillator

aim, or remote traffic in aim) is detected, the CNTRL

oven in 1A14 is at the correct temperature. In addition,

ALARM indicator lights red and an audible alarm is

a synthesizer monitor signal is applied from 1A14 to

heard over the loudspeaker. The RESET pushbutton on

alarm monitor 1A5. This signal indicates if the radio

1A15A8 or the external alarm disable switch is used to

frequency oscillator and the standard radio frequency

silence the audible alarm; however, the red CNTRL

oscillator contained in 1A14 are phase locked. If an in-

ALARM indication will remain until the alarm condition is

phase lock condition exists, the SYNTH LOCK indicator

removed. The WAVEGUIDE SW indicator on 1A15A8

on 1A15A8 lights green. An out-of-phase lock condition

is lighted green when Switch, Waveguide SA-1679/GRC

causes the SYNTH LOCK and CNTRL ALARM

is set to the ANTENNA (NORMAL) position and lights

indicators to light red. The 284.375 to 303.125 MHz

red when the SA-1679/GRC is set to the TO LOAD

output from 1A14 is applied to the times 16 multiplier

(TEST) position.

chain which is comprised of transmitter amplifier-

frequency multiplier 1A11, coaxial circulator 1HY1, and

(3) Attenuator assembly 1A3 provides

transmitter frequency multiplier group 1A10. The signal

attenuation and phase shift circuits for the to radio pcm

is amplified and multiplied to 1137-1213 MHz in 1A11.

and attenuation to ow signals. A detected ow test signal

The signal is then coupled through 1HY1 to 1A10.

from 1A3 is applied to the metering circuits on 1A15A8.

Coaxial circulator 1HY1 provides isolation between the

The pcm and ow output signals from 1A3 are combined

frequency multiplier circuits. Transmitter frequency

at the output of af-rf amplifier 1A4. The pcm signal is

multiplier group 1A10 multiplies the 1137 to 1213 MHz

amplified in 1A4 and the combined pcm and ow output

signal up to the 4.55 to 4.85 GHz local oscillator

is applied to 45 MHz low pass filter 1A6. The 4.6 MHz

frequency for application to transmitter frequency mixer

low pass filter shapes the pcm signal before it is applied

stage 1A9. Detected signal levels in the times 16

to radio transmitter modulator 1A8. A detected traffic

multiplier chain are applied to the metering circuits in

level signal (representative of the input to 1A8) is fed

1A15A8. The 1137 to 1213 MHz output of 1A11 is

back to the alarm monitor 1A5 through attenuator

detected (ampl-mult) within 1HY1 and applied to the

assembly 1A8. If the traffic level signal is present

metering circuits.

The 2275 to 2425 MHz signal

(normal condition), alarm monitor 1A6 causes the TRAF

generated by the 2nd frequency multiplier circuits in

indicator on 1A15A8 to light green. If the traffic level

1A10 is detected (2nd mult) and applied to the metering

signal is absent (alarm condition), 1A5 causes the TRAF

circuits. The 4.55 to 4.85 GHz output generated by the

and CNTRL ALARM indicators to light red. The traffic

3rd frequency multiplier circuits in 1A10 is detected

2-5