I'm playing around with a loaned 756 Pro III, and have a question regarding its tuner. I have no experience with Icom rigs, so please forgive me if this comes across sounding stupid. Here's what happens - my antenna system gives me a good match with a fairly low SWR; probably in the 1.2 - 1.5:1 range. There are some losses in the transmission line due to a poor ground system. I'm using a 1:1 balun at the antenna feedpoint to compensate and to also decouple the feedline. When I turn the Icom's tuner on, power output is reduced from 100W to about 85W as verified on a calibrated forward power meter. I test by sending an unmodulated FSK carrier. When I turn the Icom's tuner back off, I get full power out. Now I've experienced output loss from built-in tuners before, but not this much. I have my K3 setting next to the Icom, and when its tuner is inline, I might lose 1 to 2 watts tops depending on band. The Icom on the other hand reduces drive by 15%. Any thoughts?