Grounding issue while calibrating tape machine?

[Matt C.]

so i've been trying to align and calibrate my Revox B77 for the first time, and i'm running into some weird issues, the main one being this: when i touch the screwdriver to some of the adjustment pots, that contact makes the VU meter jump up or down a few db. it doesn't happen with all the pots, but definitely with the "Repro Level" and maybe a couple others. I assumed this is a grounding issue, but i'm not really sure (it seemed like it jumped around differently based on whether my other hand was touching the metal frame, what type of screwdriver i was using, whether my feet were touching the ground, etc). anyone run into this problem before? any easy solution?

[JohnDavisNYC]

you should try it with a non-conductive plastic screwdriver... one of those 'tweaker tools'... i'm sure someone else will chime in with the best place to buy them.

i use a metal mini-screwdriver for lining up my A80, and it doesn't seem to be a problem, but i know that for many people/machines, it is.

john

[CurtZHP]

Adjustments like that should be made with a fiddlestick, otherwise known as a trimpot adjustment tool. It's essentially a plastic (and therefore non-conductive) screwdriver.

That's a very common situation, so I doubt there's any grounding issues with your machine.

[CurtZHP]

Toaster beat me to it. ("Great minds" and all that!)

[Matt C.]

great, thank you

[The Scum]

Because I hate to think what Google would give you if you searched for "tweaker stick":

http://parts.digikey.com/1/parts/745515 ... -t000.html

[CurtZHP]

Because I hate to think what Google would give you if you searched for "tweaker stick":

http://parts.digikey.com/1/parts/745515 ... -t000.html

Fiddlestick makes for very entertaining results.