[Elecraft] K3S - High SWR on 6 Meters

[N4ST - Jim]

It's a puzzler.
CW is fine.  Even 100W key down CW is fine, which I don't normally run on 6M.
Can't figure out why CW is OK, but FT8 "creates" high SWR.
Problem did not exist before replacing the LPA and PA.
__________ 
73,
Jim - N4ST

-----Original Message-----
From: elecraft-bounces at mailman.qth.net <elecraft-bounces at mailman.qth.net> On Behalf Of Mike Fatchett W0MU
Sent: Monday, June 13, 2022 15:02
To: elecraft at mailman.qth.net
Subject: Re: [Elecraft] K3S - High SWR on 6 Meters

What is the 6m antenna, how far away is it from the xmitter? Sounds like 
an issue with a balun or matching overheating with the stress of FT8?

I would hook the K3 up directly to the 6m antenna or the dummy load.  
Something is certainly acting odd.

W0MU

On 6/13/2022 2:07 PM, N4ST wrote:
> So, received a new KLPA3A & KPA3A from Elecraft in exchange for my old ones
> plus $$.
> Installed the new KLPA3A & KPA3A and passed LP and HP TX Calibration.
> My 6M beam measures 1.06 SWR on analyzer.
> CW Key down, 100W, I get 1.2 on external SWR meter and 1 bar on K3S SWR
> meter.
> With FT8 I'm OK for 1 or 2 transmits and then I get infinity on external SWR
> meter and full scale on K3S SWR meter, but full power out.
> If I switch to a dummy load, I get zero power out (fold back?)
> If I operate FT8 at 8 watts with the beam, I get 1.2 on external SWR meter
> and 1 bar on K3S SWR meter and 8 watts out.
> Going back to CW full power seems to perform a reset.  Everything still fine
> in CW, but now FT8 is OK for 1 or 2 transmits and then high SWR returns.
>
> Any advice?
> A spur/oscillation in the KPA3A?
> A relay stuck/not switching?
>
> My TenTec Eagle is carrying the load for me during these 6M openings.
> (46 states worked in last few weeks)
>
>
> ___________
> 73,
> Jim - N4ST
>
>
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