[Elecraft] K3 SWR Readout Accuracy Question

[stan levandowski]

On my newly assembled kit K3/10 without the internal ATU, I've noticed 
that the SWR readouts are "higher" than those on my K2 which agrees with 
my analog inline meter.  Into a 50 ohm dummy load all three readings are 
1.0:1, but on an actual antenna the readings differ.

For example, where my K2 and  the analog meter read 1.4:1, the K3 says 
1.9:1.  this variance increases as the SWR increases and decreases as 
the actual SWR decreases, hence the agreement among all three measures 
on 1:1 when operating into a dummy load.

All readings taken at 5 watts, same antenna, same  SG-237 autocoupler, 
same cable routings, and the internal ATU in the K2 bypassed.  The only 
variable is the actual 48"coax jumper going from the K3 to the patch 
panel.

I just finished the K3 yesterday so I am just a K3 beginner. However I 
could find nothing in the manual about SWR calibration.

Any pointers would be appreciated.  Other than this, everything appears 
to be working great and the K3 DSP is fabulous.

Stan WB2LQF
K3 #5244