Re: Any known issues with the 577?


Hi Eric,
A while back I posted my experience trying to follow the procedure in the manual to adjust the storage voltages. I found it very confusing to follow and the 4 or 5 trim pots that need to be adjusted all seem to interact with each other. The whole thing was very frustrating. In the end I simply adjusted them based on what I saw on the screen until I found a combination that seemed to be acceptable to me. I would love to have someone who has actually done this walk me through the confusing parts in the manual.

Dennis Tillman W7pF

-----Original Message-----
From: [] On Behalf Of Eric
Sent: Tuesday, February 11, 2020 8:47 PM
Subject: [TekScopes] Any known issues with the 577?

So along with the 576’s that I am trying to rebuild It seems that a 577 D1 and decided to call my lab its resting place for now. It is in pristine condition given its age and the chips are date coded 91 so it seems to be one of the very late models. The good news is the tube is nice and bright with good visibility at about ½ intensity. They only issues I have found with it so far was the storage switches were slightly gummy and needed to be cleaned so they have been drenched in and exercised. Also it seems the looping capacitor in the 177 has locked complete solid other then that all the controls “feel” free and mobile. And there is 0 dust in the unit it looks like it has sat on a shelf for 30 years. Is there any known faults in a 577 like there are in a 576 that I need to worried about for this unit to be serviceable for the long haul? If there is noting there and I can repair the 177 I am going to run it through the performance check and Cal procedure then learn how to maximize its potential on the bench.

Dennis Tillman W7PF
TekScopes Moderator

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