For Beginners More
As well as building a lot of my own radio gear I got a dab hand at adapting PMR radio equipment to work on the amateur bands, most of the early Radio's I modified as projects where Pie PMR radio's, The Pie Pocket phones. The Pie Ranger, The Westminster etc etc.
These where all favorite Radio's of mine and listed below are many of the Pye PMR Range, they came in High Band, Mid Band and low Band versions and all could be modified for either 4M, 2M or 70cm amateur band working, the age range of these varies from the early 70's to late 80's but all where very well built. (more below).
The trick was then to re-tune the IF Strip and other associated tuned circuits to make the radio work on the chosen band 4m for a low band PMR, 2M for the Mid range, and 433.00 for the High Range PMR's.
The ones that I had the most dealings with where the Cambridge, Westminster and PF1 Pocket phones, and without a shadow of a doubt the Pocket phones are the most difficult to modify being so compact it is a bit of a challenge, but once you modified one or two you get the knack, also the transmitter and receiver are separate units so you have two units to modify.
The Westminster and Cambridge are a bit more straight forward and fairly easy to work on, even the single channel units are easy to adapt to multi-channel radios by fitting a board with several crystal sockets on it and adding a rotary switch to select the crystals one at a time the job is cracked, simply feed the boards output to the single crystal base on the main unit board, simple then, I have even made one of these units remote controlled, by making the channel selector switch driven by a stepper motor and driving the stepper motor from a remote control unit, clever stuff and it did work fine, this was an experiment that when well and the reason for it was so that the main unit could be mounted out of the way, say in the boot of a car and the remote head could be mounted on the dash board, then by simply pressing a push switch on the remote head the rotary switch would select the appropriate channel.