Read about this repair by our own Jeffrey, fixing an old-school CB radio setup.
A member arrived at the space one evening with a pair of CB radios: a Philips 369 (22AP369) and a MARC/CB base station (AP569). It’s hard to pin down the exact year of manufacture, but they likely date back to the 1980s. The two radios and the base station were mostly working, but with a few issues. One radio had no sound from its speaker, and the base station wasn’t outputting any power. Time to open them up.
Power Problems
Four screws and we’re inside. The base station revealed a transformer, an audio amplifier, and a nice fuse holder — with a clearly blown fuse, I could see without even taking out the meter. It was a 220V / 100 mA fuse, which I didn’t have on hand, so the repair was put on hold for a while.
Once I sourced a new fuse and installed it, it blew straight away. So did the next three.
In the end, I increased the rating on the fuse from 100 mA to 200 mA, and it held up. I adjusted the output to 13.8 volts, and it seemed to settle down. Maybe it’s just the age of the components that’s causing it to draw more current than expected?
Radio Repairs
Next up: the speaker issue. The sound worked perfectly on an external speaker, but nothing from the internal one. I noticed two mystery wires someone had added to the radio at some point. Curious, I opened it up.
I found a spare speaker in my stash with the same resistance (8 Ω) and rated for 0.5 W. It looked similar in size — the wattage might not be an exact match, but it was worth a test. A few crocodile clips later, and I had sound. Turns out the original speaker was just blown.
A little soldering and the new speaker was in. As for those mystery wires? I chose to embrace a little bit of mystery and just taped them up safely. Sometimes it’s okay not to know everything.
Antenna Adventure
Maybe I look like a radio person now. At the last Repair Café in Blanchardstown Library, someone randomly offered me a CB radio antenna — without me even mentioning radio! It was missing a few parts, but it worked well enough for testing.
With that, both radios were working again. I might be a few decades late to catch any actual CB chatter, but this was a fun little repair project. To actually transmit between the two radios, I’d need another antenna — but that’s a task for another day.
Check out our gallery for even more photos of the repair. Photos here.
Got something old and broken?
Join us at a future Repair Café or electronics night at Tog Hackerspace and bring it back to life, or at least enjoy taking it apart!