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
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