Rogerio,
Beamfinder switch is a sore spot in a LOT of tek gear. Clean and lubricate if you even suspect a problem with it. On the 576 the "cal zero and invert" switch pack is a realy soar spot and caluses lots of bizarre issues with the trace.
Zen
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-----Original Message-----
From:
[email protected] <
[email protected]> On Behalf Of Rogerio O
Sent: Thursday, January 13, 2022 11:27 AM
To:
[email protected]Subject: Re: [TekScopes] tek 577 non linear behavior in both vertical and horizontal deflection amplifiers
Thank you for teh replies.
My board is the new model (670-4126-00).
I have measured all the resistors, but without desoldering one leg and they all seem ok.
I am suspicious of S1125 (beam finder), which should be NC, connecting the -30V to the circuit.
If it is open, R1125 will be inserted in series with the -30V supply, limiting the current to both sections to keep trace in view.
It seemed that I could obtain a linear behavior of the circuit yesterday, but it was very late at night and I have to try again.
I will post my findings after more testing.
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