Jeff, thought you might be interested in this back story. What happened was this: During assembly at Ameritron, a washer was dropped inside. While I had it for 4 months, all was well. Then, I had to do some cable house keeping, and I moved the amp a little on the table, slid it over a bit. I turned on the amp, and a large flash appeared. Turned out to be that washer had landed next to that tube and arced. So Ameritron (MFJ) told me to send it back, because even though I had only one bad tube that I could see, the arc could have caused other damage. So they sent a FedEx call tag for free return shipping, and a new amp arrived at my door. Outstanding customer service by anyone's standards. 5 stars IMO. So I got the new amp going after reseating the tubes and reinstalling the Grid Protection Board I paid extra for . No problem. Everything was working great until it quit, no output. The head engineer got on the phone with me, and with the cover open and the switch bypassed (I know, I know...), he had me do a number of tests, mostly visual, but with and w/o my equipment also. It took about an hour to exhaust his suggestions based on the results. So they're sending another call tag, and this time I'm not removing the Grid Protection Board, so they can see it all. I have to say that the service was outstanding. Regardless of opinions on Ameritron/MFJ, poor customer service is definitely NOT a reason not to buy their products. And also, after listening to the work that RF Parts puts into the tubes to make sure you get a well-matched set of tubes, I decided to keep those as spares. People are really trying harder nowadays to keep the customer happy and do whatever they can to help. A little off topic, but I've received the same quality service from HRO and LDG Electronics. Off my soap box. So I'm 100W for awhile until someone figures out what's wrong with the last new one. My friend, a retired RF Harris Communications engineer, feels it's the output relay, but we won't know for sure until they look at it. Maybe I should have picked another amp, however. I don't have the bucks for a Palstar, which would have been my next choice.