[Elecraft] TxMon and K3 (tuner bypassed) SWR missmatch

[dmoes at nexicom.net]

 Thanks  for replies


I will borrow a Bird meter to see what it say  but I think in this 
case the error is in the K3 and not the P3.      as one mentioned a 
reading of 1:1,1 vers 1:1,2 is neglegable  but this is a error by a 
whole number   1:1 vs 1:2

My concern is that if its really a 1:3.5  and it thinks its a 1:2.5  
is the K3 still doing its job for protection  or is this protection 
sensed elswhere.

The coax between the K3 and the sensor is about a foot  so very close. 
 but as some said it should not be a big difference.
and I understand that the K3 is probably one of the most tolerant rigs 
out there for SWR.    My concern is when I am using an antenna say a 
doublet  where the tuner is not able to get it to a perfect match.  
say only to a 2:1 where if the K3s SWR internally is misreading it and 
its really a 3:1  that is getting  a little out of its safe zone and 
it should start to roll the power back   or will it?  if its reading 
lower than what it really is it may not roll the power back as early 
as it should.



David Moes
VE3SD



On Friday 04/11/2016 at 6:59 pm, dmoes at nexicom.net wrote:
>
> I recently installed the TX monitor in my P3 and have a discrepancy
> with the SWR reading between it and the K3
>
> with a dummy load connected the P3 and K3 read 1.12 and 1.0
> respectively   a level of error that is to me quite acceptable.
>
> however  when connected to an antenna  I will see the SWR on the K3
> often close to 1:1   when the P3 will show up to a 1:2.   as the SWR
> climbs above 1:2 on the P3  the K3 reading will track it fairly
> closely but about a level of 1 below.  example
> K3 1:1  P3 1:2,
> K3 1:1.5  P3 1:2.5
> K3 1:2   P3 1:3   and so on
>
> Note that this is done with the KAT3  bypassed of course.
>
> it made me wonder which is correct.   so I put in a meter.   old but
> faithfull KW electronics meter seems to track much closer to the P3's
> reading  which makes sense since the chances that my dipole would have
> a wide are at a solid 1:1 match before climbing as I move away from
> resonance  makes me wonder if the K3's SWR readings are out of
> calibration and if this can be adjusted.     my concern is that I may
> be excepting the SWR from the KAT3  when it may be in fact a little
> too high for the amps safety.
>
> The power readings from both seems to be quite close.
>
> Any thoughts?
>
>
>
>
>
> David Moes
> VE3SD
>
>
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