Rebuilding a Tek 577

[Zero Cool]

Anyone have any experience rebuilding or repairing Tek 577 Curve tracers? I have 2 here that power up, but definitely do not work correctly. and a friend of mine has one in about the same shape. Between the two of us and the 3 units we hope to get 2 running. I would guess a recap of the power supplies at least are in order??

Anyone know of common ailments for these? the screens on both of mine appear to be ok. clear and bright.

I do have the schematics.

[Findm-Keepm]

I've used 577's in the past - are you using the correct adapters for the devices? (Transistor adapter, etc...)

The adapters operate an interlock - I've seen this stump techs in the past. The complete operators manual is on the BAMA archive mirror.

Tek used some pretty stout parts - the collector supplies usually are the only power supplies that go on the CTs - both the 576 and the 577 were prone to collector supply failure. I seem to recall them being simple to fix, and quite standard in design - emitter pass transistor configuration on the 577.

If it was a 576, the shaft couplers would be suspect, but the 577 doesn't have them IIRC. They are the little nylon U-joints that couple the front panel knobs/shafts to the switches and potentiometers inside. They are hard to find, for sure.

The Tek diagrams give voltages for a given operating condition - I'd start there, looking to see if anything is missing. Just make sure you play it safe and also ensure the adapter-interlock isn't keeping the voltages from being present.


Good luck with the beasts!

Cheers!