Looking at the schematics for K2(A) and K2(B) and the resistance checks on page 27 for both versions you will note that both indicate J1 pin 3 is ground (0 ohms). This is correct for those models less than 3000, however, those above 3000 have the mod that got rid of the scratchy audio, and thus there is no ground and should read the same as the other pins of R3 (AF POT). Rich, KE0X