A friend gave me an older Kenwood TM-701A mobile unit that had been sitting around unused for many years. I’d been looking for a second unit to leave at home so I wouldn’ t need to swap out my Yaesu from the car as often, and it seemed like a perfect fit.
Worked great, except for one minor detail: as soon as you turn it off it forgot everything. Current settings, programmed channels, everything.
Well, that’s a pain.
So I investigated what it might take to fix that. Basically, much like an older computer, a small button battery needed to be replaced. Fair enough.
Except that you basically have to disassemble the unit to gain access to the battery.
This is what a disassembled radio looks like. Every piece you see here on my desk had to come off to get access to the battery you see on the small circuit board at the top.
To top it off, the tolerances for that battery’s width are near zero. Put another way, my soldering skills could not both solder in the replacement battery and have everything fit back together.
Fortunately, after sleeping on it, I had a flash of insight. If I could find a battery holder – for any battery than put out 3 volts – that was small enough, there was plenty of room elsewhere in the rig. I visited the local electronics and surplus store, and they had exactly the holder for the exact same battery that was to be used originally. A little wire and a little double-stick foam tape to place it had it all put together:
I put the radio all back together, and *poof* working radio with memory.
And as a bonus, in five or so years, the expected lifespan of the battery, I only need to remove the top of the case to replace it.