DIFFERENCES BETWEEN MODELS/SILICON VERSIONS.

TM 11-5820-401-34-3/0967-LP-432-3060

1-10.

EQUIPMENT DATA.

The following publications cover R-442(*)/VRC equipment data:

1. TM 11-5820 -401-10-1

2. TM 11-5820-401 -10-2

3. TM 11-5820-401 -20-1

4. TM 11-5820-401 -20-2

DIFFERENCES BETWEEN MODELS/SILICON VERSIONS.

1-11.

This paragraph contains information covering redesigned R-442(*)/VRC modules using silicon

semiconductors in Iieu of germanium devices. For details of model differences affecting operation

(controls, pushbutton tuning, etc) refer to TM 11-5820-401-10-1.

Silicon modules are considered to be throw away items, however all silicon modules replaced shall be

returned to depot for final disposition.

MODULES CONTAINING SILICON SEMICONDUCTORS

Modules equipped with silicon semiconductors are identified by the suffix letter A. For example,

A5200A denotes a silicon version squelch amplifier. The A5200 is the germanium version of the same

module.

It is possible that radios in field use might be equipped with a combination of germanium and silicon

modules.

Receiver Silicon Modules

A3500A

CRS limiter

A1400A

mixer assembly

A3600A

CRS hunt discriminator

A1500A

local oscillator

A3700A

CRS phase discriminator

A1600A

tuner power supply

A4100A

first and second IF amps

A2000A

CRS oscillators

A4200A

IF amps and limiter

A2100A

voltage regulator

A4300A

audio and squelch preamp

A3100A

CRS harmonic generator

A5100A

audio amplifier

A3200A

CRS balanced mixer

A5200A

squelch amplifier

A3300A

CRS second mixer

A5300A

squelch filter

A3400A

CRS first and second IF amps

INTERCHANGEABILITY OF MODULES

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

Squelch Amplifier A5200(*) and Squelch Filter A5300(*)

The germanium version of the squelch amplifier must not be used with the silicon version of the

squelch filter, nor can the silicon squelch amplifier be used with the germanium squelch filter.

Any individual radio must be equipped with either an A5200 and A5300 or an A5200A and A5300A in

matched pairs.

ALINEMENT DIFFERENCES

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

procedures.

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