[Elecraft] K2 - Sideband Issue??

[Jim Harris]

Hi,
My K2 S/N 47XX is about 6-7 years old and has functioned relatively well since I built it.  A few days ago I attempted to use it to check into a local 10 meter net and was told I was on lower sideband.  The display indicated upper sideband, "U" as it should on that band.  The displayed frequency was the usual net frequency.  I changed the mode to "L" and was still unable to check into the net.  
My initial thought was that the last time I adjusted the CAL FIL I had setup on the opposite sideband although I've used the radio since with good success.  Then I remembered the "OP1" filter is used for transmitting and is not adjustable so that seemed to rule out setting up on the opposite sideband.  I"m aware there is a frequency inversion on 15 meters and above and have though the problem might be associated with that.
This past weekend in the Colorado QSO party I operated portable on 20 meters and logged 76 Q's so that band seems to be transmitting and receiving properly.  I've reviewed the K2 troubleshooting procedures in the manual as well as some on line sources and have not found anything that relates to this problem.
I sure would be appreciative to anyone who can shed some light on where to start to resolve this issue.

Take pride in the USA. 73



Jim, W0EM