[Elecraft] K2 Problem

[walter renner]

I have discovered a problem with my K2 #3511 which has all the latest updates, and has been an excelent radio for the last couple of years.  While using the K2 in the contest this weekend, and operating from 40  meters and up using my center fed dipole that is 250 long fed with 450 ohm ladder line and 4-1 balun on all bands, when I run the power control up on the K2 so that the radio switches to high power I get intermod at the point of transintion form low to high.  I do have the KAT100 tuner in line and it tunes well on all bands. I realize that the KAP100 is using diode switching in the ant changeover circuit. Is it possible that rectifaction is happening with local broadcast stations, and why should this start up at this time? is it possible that the switching diodes have failed? The intermod is enough to take out all but the strongest stations. I can eliminate the intermod with an external T- match home brew tuner.  Any ideas?
K0ARO
Kurt