[Elecraft] Using the K3s Tune button causes a growing SWR on my KPA500
Victor Rosenthal 4X6GP
k2vco.vic at gmail.com
Fri Jul 15 23:15:52 EDT 2022
Something in the antenna system is heating up. Ferrite
baluns/transformers are likely culprits.
73,
Victor, 4X6GP
Rehovot, Israel
Formerly K2VCO
CWops no. 5
http://www.qsl.net/k2vco/
On 16-Jul-2022 05:53, Peder Kittelson wrote:
> When on 80 meters, the longer I hold the tune button down the higher the
> SWR goes to the point the KPA500 folds back with warnings. I don't usually
> hold down the tune button longer than about 5-6 seconds.
>
> I use a Manual Palstar BT1500A tuner which does a good job of tuning my
> EFHW wire antenna. So the initial tune is very good. I sometimes will hold
> down the Tune button on the K3s for maybe 5-6 seconds with the initial tune
> at 1-1 SWR.
>
> The KP500 first shows a 1-1 SWR. Then 1.2-1, 1.3-1 and so on. I stop when
> it reaches 1.5-1.
>
> I suppose that initially the transmitting wire sends out the signal and
> over time the current backs up. I have torroids in place to prevent RFI
> coming back down the antenna transmission line.
>
> I only use the system for CW. So when I send, the problem does not
> escalate to the point of a dangerous SWR.
>
> I wonder if this is a normal problem when holding the tuning button
> longer? And since I do not hold down the key for a long period of time it
> doesn't develop.
>
> Still, I am looking at solutions. And I am concerned.
>
> Your thoughts?
>
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