Just ordered a cable for my K3 to the THP amp and set the amp to Yaesu. Works super. Now if THP could change this to Elecraft. that would be sweet. However, the firmware isn't updateable I don't think so I will have to look at Yaesu. The only Yaesu I have left is a VX3R. J 73, Bill K9YEQ K2 & KX1 (Field tester); K3; W2; mini mods