G'day all, I love Ham Radio and I love electronics as a hobby, but has anyone ever had a weird and/or intermittent radio system fault that seems impossible to solve? These kinds of faults always seem the weirdest and hardest to solve! My IC-718 has long had a strange 20 m 'no transmit' fault that makes no real sense except that using a 4:1 'hybrid balun' (with balanced line) is generally successful. Using any other type of balun often causes the issue to appear! I have no idea why? It is totally bizarre. Any ideas? Regards, Felix vk4fuq.