BK Precision 2830 3 1/2 digit DMM multimeter restoration

[dlucy]

I've set up a tiny work bench to keep me sane and my first project is restoring a "looks like a 70's blender" DMM from B&K Precision.


The BK 2830 DMM is pretty simple, based around a temperature compensated Zener diode, and will give me enough work to remember what all Test Equipment I must have on the bench and what I can leave stowed away in the storage bin.

 

[dlucy]

I was thinking I'd replace the entire power supply with one of those tiny switching poser supply boards for $1.97 from China, but this one has more than just one voltage and rail, so I'll just leave it be.

 

[dlucy]

The power connector, though, is not standard, so that will have to go (well... it will stay and be capped off and I'll add a modern AC inlet)

 

[dlucy]

It only needs a couple of electrolytic caps and a few tantalum caps replaced, but I'll replace the Zeners while I'm in there... well, maybe not the temperature compensated one....

 

[dlucy]

It's a good thing I don't have any kitchen appliances on the bench as I'd never find the B&K DMM if I did....

 

[Mumbles]

Just curious but what's the long black with yellow stripe snap in component? Looks like a super fuse or something.

 

[dlucy]

Just curious but what's the long black with yellow stripe snap in component? Looks like a super fuse or something.

I was wondering the same thing when I first opened it up. I was hoping for some cool, exotic component that helped this DMM be cutting edge or better in some way, but turns out its just a 1kV 2A fuse for the input.

 

[arts]

The power connector, though, is not standard, so that will have to go (well... it will stay and be capped off and I'll add a modern AC inlet)

View attachment 3339795

That power connector is indeed standard; you're just sixty years too late

I have lots of those power cables, they were very common on HP gear from the sixties onwards. They used to cost lots, even used, but nowadays I imagine they have a hard time giving them away..

 

[dlucy]

The upper board, the display board:

 

[dlucy]

Someone, at some time, had put in a 33 uF 100 V cap for C4... where there is never anything like that kind of voltage... and the capacitance is too small... so it'll get the correct replacement.

Marcam, Marcon? never heard of them