Anybody Have Any Experience With Fixing d'Arsonval Signal/Battery Strength Meters/Circuits?

[CK-722]

Got a used Sony Portable on eBay. It works well considering it is nearly 50 years old. I had a similar Sony Portable with a similar issue-the Battery/Signal Strength meter had problems. The first one was pinning erratically. This one started out at zero and gradually increased to about 70 percent scale deflection. Sometimes, when I would cross a strong signal, it seemed to wiggle a little. I'm going to get the repair manual. It behaves like it's reading the voltage across a charging capacitor, not the signal or battery level. I took the batteries out to see if it will discharge and the meter goes back down. Any thoughts or ideas? I don't think its the meter movement or coil, or it wouldn't show that assumed charging effect. A broken spring would probably show variation on tilting on its side in both directions with gravity.

[CK-722]

When I checked today, the meter still showed the same deflection, with no batteries, making me wonder if the meter movement is involved.

[SolarMax]

I used to sometimes encounter erratic meter performance due to static charges on the meter face, that were difficult to discharge. Behaved Like a large flat glass or plastic capacitor. Sometimes touching a grounded clip lead end to the face would drop the needle back to zero. I recall seeing a few meter enclosures that had some sort of metal or foil internally attached to the face material to drain off such charges.

[Ed Joseph]

Indeed, what SolarMax said. Plastic meter faces are notorious for that. I have a Simpson 260 with the plastic lense bezel which says right in it do not wipe this lense... I always took a small chunk of foil and grounded it with a test jumper and them lightly pressed it flat to the lense. Most of the time it would work, sometimes I would have to rub a drop of spit on it and try again.

[WOHO]

For the heck of it, pull the batteries, connect a clip lead to short the battery power, turn unit on and off, and then remove clip lead, install batteries and give it a go.
Ed Joseph is correct about trying to ground some genuine metallic/tin foil behind the movement; I'm not sure about the saliva part though