Amp Meter acting funny

[Lynn Russell]

I fitted a milliamp meter to my machine about a year ago. Didn't want to overdrive the tube. Typical setup that everyone does. Bought a simple 0-30 ma panel unit and mounted it in the machine case just below the control panel. Connection runs from the low voltage tube end to the meter and back to the power supply.

Works great except for one thing. I've noticed recently that if I touch the top of the plastic faceplate the needle jumps to some random ma reading. Usually 4 or 5 ma setting. If I rub my finger over it I can make it wiggle and jump to another setting. After time is changes and drifts back. I am assuming I'm introducing some sort of static charge to the mechanism in the unit.

Should they do this? Does not seem like they should do this. Do you think it's going bad or is this something other people experience also?

[Pete Cyr]

The meters are very sensitive - when you rug the faceplate you are inducing a charge via static electricity and the coil in the meter is sensing the voltage and therefore creates a potential moving the needle...it is working correctly.

Don't rub it and all will be well