On Thu,3/9/2017 1:11 PM, Richard Lawn wrote: > Or am I missing something? I'm guessing that that amp is a POS. You can filter harmonics, but you can't filter IMD. I'd throw it in the trash. The SWR issue is likely because the input circuit is tuned for 11M and doesn't pass whatever frequency you're trying to drive it with. 73, Jim K9YC