[Elecraft] K3 - SWR Indication

[Geoffrey Downs]

In the past week I've been tuning and pruning an inverted V dipole I've put 
up for 40m, fed with coax. The job isn't finished yet but I'm noticing 
significant differences between SWR readings on my K3 and an external 
LP100A.

For example: At 7.000 MHz the K3 currently shows 1.2:1 and the LP100A 
2.00:1. At 7.200 MHz the K3 shows 1.0:1 and the LP100A 1.33:1. Both agree 
that it's 1.0:1 at 7.145 MHz. My MFJ 259B shows similar readings to the 
LP100A.

The differences seem more than one would expect from stray impedance in the 
KAT3 as referred to when this subject was brought up on the reflector in 
January this year.  I've not made direct comparisons like this before so I 
don't know if it's a recent phenomenon with my K3 (S/n 266) or has always 
been so.

The readings were taken with PWR at 15w and the LP100A coupler connected to 
ANT1 with a back-to-back PL259 adapter. ATU was of course in bypass mode. 
Firmware 3.11.

What do others see?

73 to all

Geoff
G3UCK