Quote:
Originally Posted by m0cemdave
Can you give full details of the meter, and a picture of the scale?
You might get lucky - somebody might have one lying around in a junk box.
Is it a Sifam 42A and if so, what's the DC resistance?
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Thanks,
Yes it is a Sifam 42A, and was one of Sifam's 'Clarity' range, no longer manufactured. The FSD is 100uA, and the D.C. res. is 1020 ohms.
The scale is not a problem, as I now have one good original scale, which I can copy (I have two RTS-2 test sets requiring a meter & one of them the scale has faded into obscurity).
I hopefully have a used 1mA version of the meter arriving next week, so I shall experiment with the op-amp driver for that.
If that proves o.k., I will probably look for another 1mA unit, as it should be a little more robust than the original 100uA type.
Someone in the USA with the same test set, did actually get Sifam to make a one-off meter using one of their
current (ouch!) range. However, it was very expensive, & needed a 3D printed bit of plastic to make it properly fit the aperture on the Ferrograph test set. At least using a s/hand meter means that it fits perfectly.
I hadn't thought of asking Sifam for a repair, but I guess that would also be expensive.
Hopefully I can get both units working again.
David