Re: Tek 7603 Followed Me Home

Chuck Harris

My guess would be the -50V unregulated supply's
filter capacitor is no longer any good.

His VAC readings are certainly Vrms as read by his
DVM, so they are 2 x 1.4Vp-p, or in other words, he
has: 13Vrms x 2.8Vp-p/Vrms, or 36Vp-p ripple on a 50V
unregulated supply. No way that can work!

-Chuck Harris

John Griessen wrote:

On 9/9/18 10:11 AM, Robert Hay wrote:
I'll re-check the voltages
50 and -50 being actual 44 and -44 is the big clue.

Chuck was saying you probably have a very much changed component contributing
the the +44 and -44 regulated voltages, so some individual component volt level
measurements are next to do.

Them both being the same 44V suggests some protection feature of the circuit is
kicking in because some
filter caps are too leaky, but not shorted or open yet.
Look for bad caps there after the regulator.

The -52 for unregulated 50 is not likely enough headroom to regulate to 50V, so that
is suspect also.
Look for bad caps there before the regulator.

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