- 2026
- Feb
- 4
Checking out some recent acquisitions - #6 - The last plastic Heathkit blue box.
This is another one of the plastic blue boxes that were recently presented in this series, and the last one I have. There were two other devices in this series - a signal tracer which goes for a lot of money when you see them, and a VOM, which I’ve never seen. This particular device is the Heathkit IG-5280 RF Signal Generator.
This device is the spiritual successor to the signal generators of yore, the ones that put out the terrible partial sine wave with 1kHz modulation. This one offers 310kHz to 110MHz (on banana jacks no less!) with 1Khz of AM modulation possible. Pretty standard stuff…here’s the front panel:
I’m not going to bother with the rest of the box, you’ve seen those before and there’s nothing different on the other two. The inside is more or less just like the others as well.
I’m pretty sure there should have been a shield on this thing. It would make much more sense to have a shield here than on the audio unit - I can even see where screws were once upon a time. Look to the right, and that hole in the chassis plate is quite mangled. This is pretty much the equivalent of the flyback cage being open on a television, there’s probably something wrong here. The stickers on the top claims that it works. We’ll see…
The first thing that’s wrong is the power switch on the back. You can run this device on batteries, just like the others. The switch itself is rather flaky, and I had to set it in the middle and wiggle it to get it to work.
The audio output is a little squished, but operational. It’s 1.04kHz, not too bad.
The RF side is a different story. I can get a little bit out, and it doesn’t really change with the selector switch. The only thing I could get that was big enough for the scope to grab was on the highest scale, and that’s not much.
The only thing I could really get was that little sinewave and some modulated garbage.
I don’t have any need for this, or desire to troubleshoot it, so into the pile it goes.
This is going into the donate pile for the Early Television Museum auction. If you want it, it should be there, assuming I can get hold of them. Otherwise, it goes to some other donation channel.
Next part of this series: Coming soon!
Previous part of this series: https://wereboar.com … -odd-heathkit-stuff/
- 2026
- Feb
- 4
A Leader LBO-310A Oscilloscope - Part 3: Considerations.
This Leader LBO-310A needs a new vertical position pot. This one:
The carbon trace on the wafer is bad, and has a worn spot right about where you’d have it centered. However, this is an oddball part. It’s got a shaft size that’s not really anything normal - as best I can tell with my crude calipers it’s slightly less than a normal 6mm. The mounting is also an odd size, I can’t find anything that fits in the hole. Things are either too big or too small.
My plan is to put it back in the hole, remove the wires, and just leave it as a dummy. I’ll put a new pot on the back. This pot right here:
While this one mounts in the hole (it’s a little small) the original knob does not fit on the shaft. I’m going to unsolder the wires on the PCB and run these to it, while mounting the pot in a small hole on the back.
If I ever find a replacement, I can just reconnect the front panel device and leave the new one on the back as a spare. I went ahead and prepped things, but didn’t feel like drilling - that’s the next part.
Next part of this series: Coming soon.
Previous part of this series: https://wereboar.com … pe-part-2-diagnosis/