Section III PRINCIPLES OF OPERATION - TM-11-5820-670-300014

TM 11-5820-670-30

1-11. DIFFERENCES BETWEEN MODELS/SILICON VERSIONS. (CONT)

INTERCHANGEABILITY OF MODULES

Germanium and silicon modules may be used together in the same radio with the following exceptions.

Only germanium versions of the following modules should be used:

First and Second IF. Amps A4100)

Audio and Squelch Preamplifier A4300

IF. Amps and Limiter A4200

AF Amplifier A5400

Squelch Amplifier A5200

Squelch Filter A5300

ALINEMENT DIFFERENCES

With the following exception, there is no difference in germanium and silicon version alinement

procedures.

Transmitter 11.5 MHz Modulator A8100/A8100A

Rearrangement of the circuit board in the A8100A silicon version has moved the shorting point for

modulator testing and alinement. Additionally, the polarity of the variable capacitance diodes has

been reversed, eliminating the 180-degree phase shift in the modulation. This permits compatible

interface with various data systems.

Section Ill PRINCIPLES OF OPERATION

Subject

Para

Page

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-12

1-6

RECEIVE MODE

Receiver Signal Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-13

1-7

Local Oscillator AFC/Crystal Reference System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-14

1-8

CRS Balanced Mixer A3200 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-15

1-10

CRS Second Mixer A3300 and Crystal Switch A2000 . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-16

1-11

CRS First and Second IF. Amplifier A3400/CRS Third IF. Amplifier

and Limiter A3500 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-17

1-14

CRS Hunt Discriminator A3600, CRS Phase Discriminator A3700, and

Reference Oscillator A2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-18

1-15

Time Delay Circuit P/O Module A2100 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-19

Gearbox Assembly A9700 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-20

RF Control Assembly P/O Module A4500 (Receive Mode) . . . . . . . . . . . . . . . . . . . . . . .

1-21

Antenna Tuning and Protection Module A1100 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-22

First RF Amplifier Module A1200 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-23

1-22

Second RF Amplifier Module A1300 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-24

1-23

Mixer and Buffer Amplifier A1400 (Receive Mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-25

1-23

Local Oscillator Module A1500 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-26

1-24

IF. Attenuator Module A4900 (Receive Mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-27

1-26

First and Second IF. Amplifier A4100 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-28

1-26

Third, Fourth and Fifth IF. Amplifier, Limiter and Discriminator

A4200 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-29

1-27

Audio and Squelch Preamplifier Module A4300 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-30

1-28

Audio Amplifier Module A5400 (Receive Mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-31

1-28

Receiver Squelch Amplifier Module A5200 and Squelch Filter Module

A5300 (Receive Mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-32

1-4