Wireless Set C42

Wireless Station C42

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General Description

The C42 is a VHF FM transceiver covering the frequency range 36 - 60 mHz, providing 241 channels at 100 kHz spacing, using the dial calibrations. Operation in between channels is quite possible. The set will work quite well on 52.525 mHz, where I have worked JA on low power.

The C45 is physically identical and works on the lower range of 26 - 38 mHz.

The C13 is a HF set of the same physical dimensions but completely different electrically. All 3 units are designed to use the same harnesses.

These sets were used in Centurion Tanks and Land Rovers FFR (Fitted For Radio).

It was introduced as a replacement set for the No l9 transceiver, during the period 1955-60. Many of the units are dated 1959.

There are 3 units - the radio, (Wireless Set C42) , a power supply (2 types - 12 or 24 volt: Supply Unit Vibratory No 12) and an aerial tuning unit (No 6).

Technical Data

The set features a crystal calibrator for frequency adjustment and the C42 is a true transceiver, with the Tx being locked to the Rx oscillator.

Transmit power is 15 watts (HIGH) and .25 watts (LOW).

Automatic level control is used on transmit and the receiver features selectable squelch. (A bulb lights when a signal is received.)

Also included is an intercom amplifier for use of the crew in the vehicle.

Automatic rebroadcast is available if the set is coupled to another transceiver.

The average range, set to set, is 3-4 miles on LOW and 10-15 miles on HIGH, using 8' rod aerials.

POWER CONSUMPTION:                                24volts              12volts
   SEND HP          8.0 amps          17.8 amps
   SEND LP          5.5                     11.8
   RX TRAFFIC    4.6                     10.8
   RX STANDBY  3.7                       7.8

The set features a variable voltage harness,which selects the high voltage tap with input voltages of 25.5 - 29.0 volts, or the low voltage tap between 20.7 - 25.5 volts.

Operating voltages are 175v for Rx and Tx (LP) and 350 v for the Sender on high power. All valves operate on 6.3v filaments, with the exception of the sender filament, which works on l2 volts.

AERIALS: The standard aerial is 8' long consisting of 2 4 foot sections. An elevated aerial, mounted on a. 27' mast is used for base applications.

The all up weight of the units is 86 lbs.

Illustrations of the set

Power Supply C42 Aerial Tuner

C42 Internal View

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© Ian O'Toole, 2009. Page created: 28/04/03 Last updated: 4/12/2009