I have a Hammarlund HQ-170A that was working fine until one day it just wasn't. It just seems like it's lost it's receive ability. I've been through the tubes with my B&K 606 and even replaced the the HF oscillator, mixers, prod. detector tubes, etc. There's plenty of audio present, just no signal. Any advice will be appreciated. Is there a way to test the IF cans, without opening them up? I don't want to mess with the film caps unless there's no other option. Thanks, john, AE9DX