My first venture into the world of transmission, SWR and antenna resonance came in 1980. It was then I purchased an AM CB radio, all very illegal in the UK at the time.
Like just about everyone in the UK, I had been fascinated by CB after watching the film Convoy. The movie brought the idea of free, easy, 2-way communication for the public into a reality.
My first real experience of CB was listening to the transmissions of locals chattering away on the illegal AM radio sets. I was absolutely fascinated by it.
It didn’t take very long to acquire a CB radio for myself, and after asking numerous questions about setting it up, I was finally on the air, still learning the lingo!
As time passed, more and more people gained access to the airwaves using the illegal CB radio sets, and the demand for a legal CB system in the UK was growing.
On the 2nd November 1981 the UK was allocated a legal CB system. This used FM and slightly different frequencies to the AM CB’s to prevent conversion of existing AM radios and reduce possibility of RF interference.
A second UHF system was also introduced using 934MHz, but due to the high cost of equipment, it had a very limited and short lifespan. These days the band is now used for cellular telephone networks.
The use of CB in the UK became a bit of a “craze”. Before very long, the CB band was awash with lots of users, thus finding a “free” channel on which to hold a conversation became all but impossible.
With this came users with low technical skills resulting in lots of radios having blown final transistors.
Blown reverse polarity protection diodes was another very common fault, usually after someone had connected the radio power feed incorrectly, the diodes gained the nickname of wally diode; Wally being UK slang for idiot.
With the complete outlawing of the “old” AM and SSB radios so that simply possessing one could land you a hefty fine, CB shops wouldn’t repair them.
With my interest in electronics this led me nicely into being the local “rig doctor”. Of course, I was taking a huge personal risk having these very illegal CB radio sets in my house.
Repairing these “blown up” radios for the local users encouraged me to learn yet more about the various circuits, how they worked and how they were interconnected and interacted with each other.
Quite a lot of my work was with SSB radios as these were quite popular at the time, mostly the Cobra 148 GTL-DX. The biggest request was to modify them to give them extra channels to cover more of the 11M band.
Of course I used to use one myself along with Bremi BRL200 linear amp and an Avanti Sigma IV antenna.
I now have the pleasure of currently owning two Superstar 3900’s in the shack to “play” on the CB bands once again.
Superstar 3900’s are modern clones of the original Cobra 148’s, and are in fact, very similar internally. Read more about my thoughts on the Ranger SS3900 here.
From CB’s and repairs, the natural progression was an » Introduction To Amateur Radio