Midland 76-900 CB27/81 Uk FM CB radio base station - repair & service pt1of3

https://www.ebay.co.uk/itm/116266271573

Now on ebay - I've finally got around to publishing part 1 of this. I bought a large batch of CB stuff off ebay or about £400. All I wanted from the lot was a pre-amp!

At first glance this set freally looks ropey, but upon opening it up It turned out to be in better condition that either of my other two & hasn't been messed with either.

Initial tests showed around 4W output but unbalaced between channels 1 & 40. RX looked reasonable. All tests done with the bench power supply. I never plug 'unknown' base station in as a faulty power internal supply could be pushing out 26 volts....and wreck the actual radio.

Behind the scenes, the large LED green display turned out to be faulty. I ended up importing two from the USA for £20. Not cheap.

Upon testing the internal PSU after changing the three capacitors, I couldn't get more than 10V out if it with one of the transistors (on the PSU boad) overheating. It turned out that a 5.6V zener diode was leaky & one had to be ordered as I'd nothing in stock under 9V.

Recorded 11th July 2024

Richard, G0OJF

Lincolnshire, UK

(C) Tango Systemsroup 2024

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