Functional Block Diagram Description of Receiver, Radio R-1467 (P)A/GRC-144(V) Demodulator and Output Amplifier Circuits

TM 11-5820-695-35

2A11 consists of video amplifier stages Q1 and Q2 and

emitter follower Q3. The composite pcm and orderwire

Demodulator 2A4

signal is applied to video amplifier stages Q1 and Q2

receives the 70 MHz IF signal from IF amplifier 2A5 and

through the TRAFFIC LEVEL ADJ control which is

demodulates the signal to provide the composite

adjusted to provide a 1.0 volt peak-to-peak output. The

data/orderwire ,baseband (video) signal. Input amplifier

composite pcm and orderwire signal is amplified by

stages Q1/Q2 provide impedance matching and

video amplifier stages Q1 and Q2 and applied to the

frequency response control. Limiter stages Q3 through

output through emitter follower Q3. Emitter follower Q3

Q6 provide amplification with amplitude limiting. A

provides an impedance match between video amplifier

Crosby-type discriminator (CR8/CR9) converts the

Q2 and the output and also provides negative feedback

frequency variations of the frequency modulated IF

to video amplifier stage Q1. The amount of negative

signal into the video signal. Video amplifier stages Q9

feedback determines the overall gain and bandwidth of

and Q10 amplify the video signal and couple the output

af-rf amplifier 2A11. The pcm and orderwire (receiver

signal through emitter follower Q11 to low pass filter

traffic) output of 2A11 is applied to Transmitter, Radio

2A3.

T-1054(P)/GRC-144(V) and to alarm monitor 2A12

which monitors the level of the receiver traffic output

Low Pass Filter 2A3. The filter assembly

signal.

used for 2A3 varies according to the data rate as shown

2-23.1. Functional Block Diagram Description of

2A11.

Refer

AF-RF

Amplifier

Receiver,

Radio

R-1467(P)A/GRC-144(V)

paragraph 2-23c.

Demodulator and Output Amplifier Circuits

(fig. 5-19.1)

Change 6

2-50.1/(2-50.2 blank)