[Elecraft] KPA500 power fluctuations

[Thomas Horsten]

Hi Poul-Erik,

It sure sounds like a fault in the KPA500 power measuring circuit in your
case, but is the output signal affected in any way? And does the SWR LED's
fluctuate/flicker as well? I had that problem and it turned out to be a bad
patch cable from the KPA500 to the KAT500. It would only happen above 100W
or so, and on certain bands/frequencies.

73, Thomas M0TRN / OV5T



On 20 June 2014 11:48, Poul Erik Karlshøj (PKA) <PKA at telepost.gl> wrote:

> For a while I have noticed that the KPA output indikations on both THE
> LEDs and the LCD display is fluctuating. The highest LED is flickering and
> the last two digits of the LCD are also fluctuating (hard to read, but at
> 500W it varies about 10W I think). It is the same at any power level from
> 20W to 500W. It is the same with the amp ON and STBY, so it seems to be a
> problem in the power monitoring circuit.
>
> It is certain that the fault is in the KPA. I had another KPA connected to
> the K3 and its power indication was steady - just like they were on my own
> KPA until a few months ago. It is the same whether the amp is connected to
> a dummy load or an antenna and I dont hear anything unusual listening on a
> monitoring K2.
>
> I did not yet have an opportunity to look at the power envelope on an
> instrument. So I dont know if the flickering is random like noise or not.
>
> I thought that may be someone else on this list has seen this fault and
> might explain what's wrong.
>
> /Poul-Erik
> OZ4UN
>
> Sendt fra min iPad
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