[Elecraft] KPA 500 Hum

Lothar Sack LotharsMail at web.de
Mon Aug 1 18:11:47 EDT 2011


The same hum here since I changed to the *RED TAP (211 to 230V).*
I had _no hum with the YELLOW TAP (231 to 250 V)_. But then I had less 
than 60V with full power.
The hum is coming out of the KPA500.
What to do?
Lothar, DJ8EW
K3 1300 + KPA500 229

Am 01.08.2011 09:33, schrieb Klaus Koppendorfer:
> Last week i assembled the kpa500 of oe6rdd
> when we transmit we hear a realy loud hum (50hz) in the rythm of the cw signals
>
> i have compared this with my own kpa-500 and there is no hum
> i have tried to loosen the big srew which holds the tranformer with no result
>
> any ideas ??
>
> 73
> Klaus
> OE6KYG
> KX1 244
> K2 1331
> K3 115
>



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