[Elecraft] Using the K3s Tune button causes a growing SWR on my KPA500

[Dave Erickson]

On 7/15/2022 9:53 PM, 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?
> 


Hi,

Are you feeding an EFHW antenna with balanced feed-line? I don't believe 
I have seen that done much.

Is your antenna commercial or home made? I'd like to see more about that.


-- 
Dave Erickson
AB0R
73