On Fri, 08 May 2009 22:18:43 +0200 vic wrote in
Message id: :

Hi,

I recently bought an oscilloscope on eBay, and I don't know if the
seller lied in the description or if it was damaged during the
transport, but the trace is completely distorted and shows strange
grid-like patterns. I made a few pictures and a little video :

http://img222.imageshack.us/img222/1984/focused.jpg
http://img212.imageshack.us/img212/6566/unfocused.jpg
http://www.youtube.com/watch?v=c5RTaTM0tJk

The shape of the trace changes when I change the y-position dial. This
makes me think the problem is in the tube and not in the electronics.

I'm wondering if this could be caused by a bent grid somewhere in the
tube ? Could it have been damaged if the oscilloscope received a shock
for example ?

I think the tube is pretty much toast, as well as the scope since there
is no way I could find a replacement tube (Tektronix 2225), but I
wouldn't mind to be proven wrong :-) Thanks.

Shoot an email or phone someone at https://www.techrecovery.com/
We have lots o' dead Tek scopes that are not worth repairing. Dunno what
they'd charge for the tube, but $75 + shipping sounds reasonable to me.
Tell them Jay sent you. Just do a bit of homework first and find out what
other models share the same tube (So I don't have to do too much digging)
and have the Tek part #. Make sure you put that info into your query.