[Elecraft] [K3] - Odd SWR readings ANT1 v ANT2

[Stewart Rolfe]

No doubt the recent Es propagation has brought the following behaviour to my attention...it's only evident on 10m for some reason:-
Screw in a PL259 type dummy load into ANT1 (KAT3) and deselect ATU. Press TUNE (10w) and the indicated swr on the K3 is 1.7 to 1.8. Change dummy load to ANT2 and select and the indicated swr is now 1.0...!
I've swapped the antenna leads on the KAT3 board to determine it's something to do with circuitry around the antenna relay and not PL259 sockets/interconnecting leads but according to the schematics each path is equivalent. Furthermore an external swr meter placed between dummy load and K3 indicates 1:1 on *both* ANT 1 and 2 so it seems to be  something to do with the way the radio is sensing the swr between the two antenna
 sockets.
I'm not at all hung up on swr but why the difference between the 2 antenna inputs - strays in the relay or surge arrestors? It also looks like the radio is 'thinking' about the power output when the swr indicates 1:1.8 and above and may cause power variations....?
Thoughts??
73,
Stewart Rolfe, GW0ETF (K3 #145)