[Elecraft] 80m KPA1500 High reflected power problems **SOLVED!**

[Peter Dougherty]

I have that exact front-end protector on the main RX line from the K9AY, but
I didn't have it on the AUX antenna. I will now, obviously.

 - pjd

-----Original Message-----
From: elecraft-bounces at mailman.qth.net <elecraft-bounces at mailman.qth.net> On
Behalf Of john at kk9a.com
Sent: Monday, March 11, 2019 1:58 PM
To: elecraft at mailman.qth.net
Subject: Re: [Elecraft] 80m KPA1500 High reflected power problems
**SOLVED!**

I am not sure how a second antenna effects the amplifier, I believe that the
K3(S) has a safeguard from some overload conditions. If your RX antenna is
close to your TX and you run HP, I would protect your transceiver from
overload by either shorting the RX feedline during TX or with a protector
such as this one:  
https://www.dxengineering.com/parts/dxe-rg-5000

John KK9A




PETER DOUGHERTY W2IRT wrote:

-------------------------

Hi folks,
FOUND THE PROBLEM....Maybe??

I have a 30 foot vertical ground-plane style antenna that I use for
diversity RX on 40 and 80, which was connected to the AUX antenna port. 
This was being overloaded by the QRO power from the TX antenna feedpoints
just a few feet laterally and 40-50' higher vertically. As soon as I
disconnected this antenna the problem went away.

NOTE that the problem only occurred on the lower CW portions of both 80 *and
40*, as I found out tonight. In the SSB sections, even on CW transmit, there
were no problems. But as I said, disconnecting the diversity AUX antenna
solved the High SWR amp fault.

So now, the big question, is there some form of filtering within the K3s to
disable receive on the AUX line during transmit, or do I have to look into a
second "front end protector" device as I have on my K9AY loop connected to
the RX IN port. Or perhaps some other valid solution?

At least I'm glad I finally have full operation back on 40 and 80!
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