Re: 2nd life for a 575 after resting for 30+ years in the attic #photo-notice


Joe
 

Hello,

Today I let the unit running for an hour at regular mains voltage and did comparison tests on a pair of BC 238 C transistors. What can I say? I am deeply impressed by the bright, sharp and stable display. That is great! Nevertheless I registered a minor problem that has to be solved: The flyback traces of the beam are "visible, too bright".

@ John: Yes I forgot to mention these sticky fan bearings. Well, a little "Ballistol" oil did the job quickly.
@Jeff: Thanks, your explanation must be right. That tells us the Tek designers did a very good job. I know a lot of other instruments where several components are tied to higher voltage levels and not any provision is done to prevent shorting or so.

BTW: All of my BC 238 C transistors produced very similar curve families, so they seem to have close tolerances. I think I will try some older OC 26 now and see what happens.
Joe

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