Re: [Hamlib-developer] K3 SWR > 2.5 at the end of every transmission.

[Nate B. <n0...@n0...>]

* On 2026 07 Apr 19:16 -0500, w2yf wrote:
> When using 4.7.1 with WSJT-X-improved and turning on the Rig data options
> of Pwr/SWR along with the stop transmit if SWR is > 2.5, every single
> transmit ends with an SWR over 2.5 (reports a 20.9:1 !!!).

That would probably be seen with every prior version of Hamlib as well.
I've also seen the glitch and it appears on my P3 with Wattmeter
accessory as well at times and with WSJT-X 3.1.0 improved PLUS as
packaged by Debian running with Hamlib 4.7.1~rc.

> Second question, is it worth addressing?

Given that the issue is internal to the radio, I'm not sure just how we
could address it properly.  One thought I had was to store and average
the last N readings but then if/when SWR really does change dramatically
during TX (water contamination, etc.), that won't be reflected properly
(pun intended).

I suspect that the firmware is doing so many things at the point of
ending TX that the reported SWR value gets corrupted.  Regardless, until
about a decade ago when remote operation became very popular and near
real-time radio control became an expectation, radios simply weren't
designed with that amount of information flow in mind.  As you note, the
K4 doesn't have the issue as it exists in the current era where near
real-time control of all aspects is expected.  Also, it has an Ethernet
port.  There is only so much data to be pushed through a serial port,
even at 38400 bps.

I appreciate your work on learning about this issue and where the
problem lies.  I may be wrong but I just see this a part of the changing
tech landscape where new expectations are pressed onto old(er) tech
that's not really worth trying to paper over.  Of course, I'll merge any
patches that do address this in a way that is helpful.

73, Nate

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