UK Clansman VRC353 VHF FM Radio

The British Army Clansman VRC353FM VHF radio uses the 30 to 76 MHz frequency range providing 1840 channels at 25 KHz spacing.Frequency selection is by digital synthesizer with an accuracy better than five part in one million over 24 months's use.

The VRC353 is housed in a rectangle cast aluminum alloy case into which it is secured by five dowel bolts one at each corner of  the front panel and one centrally located in the rear wall of the case , the latter having a sealing washer.

Sealing is provided by toroidal rubber sealing rings, between front panel and case and at each blower outlet in the rear wall. Additional sealing is provided at the blower outlets by a rubber and metal seal located beneath this sealing rings.

A single frequency selector control allows rapid selection from the 1840 channels available even when using protect gloves. In darkness the frequency can be selected by click-counting from zero. Failure to select a frequency within the frequency range of the radio will cause the dial light to flash and an alarm to be heard in the earphone.

Tuning is automatically controlled from the synthesizer logic. Retuning times is within ten seconds during which time transmission is not possible and the dial light will continue to flash as a warning. The radio reaches operating conditions within a minute from a minute from switch-on, after which the frequency stability is within five parts in one million.

The radio uses tube technology in receive front end and RF final amplifier. It uses two stage of  RF amplifier
with six double tuned circuit coil in receive front end. So high selectivity is obtained. Power output is minimum 50 Watt on all frequency.

Technical Specifications

Operation parameters

Range: Up to 30 km with a recommended vehicle antenna. When used in a static role greater distances may
be obtained by the use of an elevated whip or inverted ' V' antenna.

Physical parameters

Height: 215mm

Width: 240mm

Depth: 355mm

Weight: 22kg

Electrical parameters

Frequency range: 30 to 76 MHz in three discrete bands:

Band 1: 30 to 40.975 MHz

Band 2: 41 to 55.975 MHz

Band 3: 56 to 75.975 MHz

Frequency Stability: 5 ppm

Intermediate Frequencies: 1 st 9.6875MHz

                                        2 nd 312.5KHz

Receiver sensitivity: Analogue: 6 db (s+n/n) for 0.5 micro V rms emf input, modulate by 1 KHz at 5 KHz

                              deviation (narrow) or 10 KHz (wide)   

                              Data: sensitivity such as to give error rates specified for corresponding input levels of

                              unfiltered data at 16kb/s.

Receiver selectivity: Rejection greater than 80db on all channels other than that selected.

RF Power Ouput: 50 Watt

Power Input: 24 Volts DC