Sounds like a bad bridge. Check the voltage before it goes through the
regulating transistors on the back (cooling fins) it should be about 25
volts DC and output from them to the power out plug should be 13.8 VDC.
If half of that bridge is bad you'll still get the 12 volts or more
output but under a load it can't keep up and you'll get that AC ripple
and voltage drop. I've been through this on a 262 and your problem sounds
the same.
73 Jeff aa8ve
On Fri, 17 Dec 1999 12:37:30 -0800 (PST) N1EU <n1eu@yahoo.com> writes:
>
> Well, the raspy cw tone on my Omni 6 has been traced
> to the 961 power supply. Under transmit load, the dc
> output of the 961 shows as much as 5 volts of 120hz
> ripple (seen with an oscilloscope). I'm no power
> supply expert by an stretch of the imagination, and
> would sure appreciate any expertise on troubleshooting
> further. I plan on testing the 47000uF filter
> capacitor, but any additional advice is welcome.
>
> The power supply audibly hums in transmit and is
> normally quiet at other times. It has gotten much
> worse over the last couple of days, as if a component
> is really in failure mode. Occasionally the hum and
> ripple aren't there and it transmits cleanly, but more
> often than not they are and it's getting worse.
>
> Best holiday wishes & thanks for any help,
> Barry N1EU
>
>
>
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