Hi,
I have a old Beckman 20MHz analog. Recently, I found out that the trace is not stable. For instance, the ground trace can not stay at the center line, and it keeps moving up.
Is there way to fix it? Or should I just get rid of it?

Best,

Dukeman

 

You need a circuit to help fix this...

 

Does it eventually stabilize?

 

Any thing is fixable. They will help you along the way. But it's not worth your money or time. Sell at the eBay. There plenty of people who can fix easy at no time.

 

A drifting trace usually indicates drift of the balance in the various differential amplifiers OR lack of stability of power supplies. Search the internet with the model number of the scope and if you are lucky, a service manual may be available.

Back in the day, we had machines that had vacuum tube differential amplifiers. Balance on these was checked/adjusted at least every 8 hours since it would have an effect on machine position accuracy.

 

After turning around the volt/div knobs several times, taking from a suggestion from a friend of mine, the traces would get stabilized after the scope is sitting with power on for a while. I decided to keep the scope.

Thanks for all our suggestions.

Best