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

[dmoes at nexicom.net]

 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