[Elecraft] Suspicious power supply

[Martin]

Hello elecrafters,
today my K2 showed a strange behavior.
About 1 minute after switching it on, it suddenly lost power for
fractions of a second, then came alive again.
Then, after 2 mins. it happened again. And again after a couple of
mins.

I tried to reproduce the failure by tapping and knocking on the case,
i shaked the radio and the power cord - nothing happened.

The radio ran flawlessly for 30 mins, then i shut it off .

I switched to the internal battery and left the radio on for 2
hours with the display set to show voltage & current.
When i returned to the shack, the display still showed voltage &
current.
Next test was running the radio with a different power supply, again
with display set to show Voltage & current.
After 4 hours it still showed v & c.
If there had been a failure in the meantime, the display would have shown the
frequency as it always does when power is back. Right?

If there is something wrong with the radio it should also fail when
battery-powered or with the second power supply. Right?

So the culprit must be the first power supply.
Either the voltage is below or in excess of a certain level for a few
ten milliseconds. Right?

Any ideas on how to monitor the power supply without staring on a
voltmeter all day? I have no scope.
The supply is a switcher.

Any comments welcome.

-- 
Best regards,
 Martin
K2 #2706                          mailto:dl1iaq@gdxf.de