BC760XLT Scanner Repair

So the preamble to the story is that I just moved into a new QTH and while my ham gear is protected by multiple ground rods and polyphasers, my scanner was not.

Now, it was a cheap scanner (found on eBay for under $50) connected to a Raspberry Pi 4. It was at the service entry point to the house and I hastily set it up. I used it to live stream audio to a web server on the Pi that I could access with my phone. The antenna was set outside, not raised up much or anything (power lines above). I just needed to pick up the local repeaters when I was away and wanted to listen in. Everything was plugged into a small UPS but I knew the antenna was susceptible. It would work for now until I can get back to it.

The very day I set out to ground and protect the antenna, I was outside trying to get things finished when a freak storm rolled up. Well glad I came in to take a break with the rain because lightning lit up my property (my ham shack was disconnected). I am sure I heard electrical arcing in the house when it hit.

Later that evening I noticed things were offline with the Pi. And as you probably guess from this title blog, my scanner was dead from the lightning induced voltage spike in the antenna. That and the Raspberry Pi were toast.

Nothing I could do for the Raspberry Pi. No way I could solder that. Next for the scanner. There were no visible marks but it did turn on with distorted garbled audio which faded off to nothing. It smelled of burning electronics. That was GOOD for me! I opened it up and poked around. The part that was smoking was definitely a problem!

Looking up the part number it turned out to be an audio amplifier circuit. That made sense why the audio went out! I also tested the voltage regulator (8V as designed according to the part number). Strangely the power supply transformer was putting out 18V instead of 13.5! At least that was within range of the voltage regulator to handle (I changed that out too).

Well I am terrible at soldering and the leads on the printed circuit board burned very easily so I decided to make a modular design (hopefully not to replace often). While waiting on the $5 part, I soldered jumper wires in the IC socket to connect to a solder-less breadboard just awaiting the IC.

Now here is the modular design in action. Luckily the age of the scanner makes for a lot of extra space in the case.

And now here is the final product. I wouldn’t want this rattling around in a mobile installation but it works well for a stationary setup. It will have adhesive to keep it somewhat fixed.