[Elecraft] KPA1500 PA Current

[Hank Garretson]

Send your email to Elecraft support. Can't hurt.


On Fri, Mar 15, 2019 at 12:26 PM Gary J Ferdinand <alaparos at w2cs.net> wrote:

> I’m in the process of checking out my amp.  I have two dipoles (40 and
> 80).  At resonance both show a 1.2:1 SWR with ATU totally bypassed.  With
> ATU on, it remains bypassed on 80, but shows only the ATU ON LED on 40.  In
> both cases the resultant SWR is 1.2:1.   SWR measurements are from the
> KPA1500 display.
>
> When I use the amp with my K3 and drive it up to 1500W, I am occasionally
> getting an excessive PA current fault at 63A.  From a cold start it’s 60A,
> but as it warms up in contest usage I find the power drops off, so I have
> to adjust the K3 to bring it back up to 1500W.  At that point the PA
> current goes over 60A.
>
> Interestingly, into a dummy load the 1500W point shows a PA current of
> only 55A.  So the 1.2:1 SWR, be it via a bypassed ATU or using the ATU, is
> sufficient to raise the PA current eventually to excessive levels.
>
> Suggestions?   I don’t want this to be flipping out during a contest.  I
> also don’t want to reduce power into what should be a totally acceptable
> load.
>
> 73
>
> Gary W2CS
>
>
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