[Elecraft] K3 : ERR TXG on 50W TX Gain Calibration routine...

[Gary Gregory]

*John,

Checked my emails later than normal for the day and so I see you have had
an issue like I had once except i discovered the jumper was indeed faulty.

Glad to see you got it sorted.

73
*
On 8 October 2012 08:31, <zendoc at netspace.net.au> wrote:

>
>
>         Group,
>
>          I think I've discovered the cause:  I noticed the SWR seen by the
> K3 at 52.00MHz is 1.2:1, whereas it's 10:1 on all other bands. This
> was shown on the K3 SWR meter and confirmed with my antenna analyser
> at the K3 antenna connector.  I did some detective work and
> discovered that the length of the (short) jumper cables connecting the
> K3, the sensor of my LP-100A and the dummy load was either having a
> transformer effect or otherwise introducing stray reactance.  The
> results was a less than perfect 50 ohm match on 52.000MHz.
>
>          I changed the length of the jumper cables just a little (swapping
> them out with  others of different length), and the SWR seen by the
> K3 came down to 1.0:1 @ 50Mhz and the Tx Gain calibration routine then
> ran perfectly.
>
>          I'm using LMR-240 ultraflex jumpers and individually, connected to
> the dummy load, they check out OK.  It's something about the total
> inter-connect length at 50Mhz.
>
>         Thinking back, I suspect I've changed the in-shack jumper
> arrangements since the last calibration.
>
>          Thanks for everyone's help.
>
>         73,
>
>         John
>
>         VK7JB
>
>
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-- 
*Gary*
*Start the day off slow, then taper off.........*
K3 #679
KPA500FT #18
KAT500FT 007
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