Frequency Allocation

During the mid/late 1980's the ROC Post radios were changed from single channel with dual frequencies for transmit and receive. To three channel radios working on a single frequency for both transmit and receive. These new radio sets allowed posts to communicate with other posts within their own group as well as headquarters. Additionally the two other channels would allow contact with posts in adjacent groups. These may have been able to relay messages back to their own group headquarters on behalf of the isolated post. The allocation of the two channels for emergency use are shown in the table below. The three letter code is the standard one used on plotting maps.

A callsign is shown for each group. However I have never heard them used in Bedford or Coventry and feedback from visitors to the site confirm they were not used. Documentation suggests that Preston Group HQ would have used the callsign M2 SN99. The M2 appears optional (Police and Fire have callsigns in the same series and often discard the M2 prefix). The post number would be added as a sufix, for their callsign.

Example of Preston calling 25 Post
Hello Sierra November Two Five, this is Mike Two Sierra November Nine Nine, Over.

The twelve frequencies allocated to the ROC were in part of the Home Office allocation of 80.000-81.500Mhz used by the fire brigade. The radio scheme appears to have been denoted as RN4.