This was an impulse purchase. I didn’t need another radio, but the price was right, and another ham was waiting to buy it if I didn’t. I had never owned or used a SB-104A and knew nothing about it. The photo above was taken as it sat on the tailgate of my pickup truck at the show. The last thing I needed was another project, but I now had one. What was I thinking?

This is the story of how I am bringing this SB-104A back to life.

This radio was missing the E board which contained the crystal filter and carrier oscillators. I knew where to get one of these, where else, eBay. So $50 later, I was the proud owner of an E board for a SB-104. It should work, right? I installed the board and applied power to the SB-104A, but nothing happened. The S meter was not illuminated, the digital display remained dark. Not the best start, but at least I didn’t see any smoke.

I download manuals and schematics from the Internet, and started to learn about the SB-104A. The SB-104 is a very simple and straight forward radio. No microprocessor or phase locked loops. Simple analog type circuitry with a frequency counter digital dial made up of discrete ICs. The printed circuit boards are very large by today’s standards, and most are only single sided. The holes in the boards for components are quite large, making the boards easy to unsolder bad parts and replace them. All in all, a very clean design that is easy to work on, especially compared with most contemporary transceivers.

Of special interest to SB-104 owners may be my LED digital display board modification! Replace your gas discharge display with a beautiful LED display for less than 25 bucks! Some assembly is required, but the results are worth it.

Disclaimer time. I have been a ham 50 years, hold an Extra Class license, and made my living as an electronic / computer technician, before retiring a couple of years ago. Tackling this kind of a project is not for everyone, but if you care to tinker, you can end up with a solid well performing radio, that you will be able to fix yourself. At least, that is my theory!

These web pages are a work in progress, and as my work on my SB-104A progresses, I will be posting updates.

If you have any questions, feel free to contact me at [email protected]

73 Chuck Harrington, K8LBH - Winter Park, FL