Hello all, I'll start by saying this is the first tubed product I've owned. I traded this little thing for a microphone. It has an 8417 tube. The guy I got it from says it should swing 100 watts, the max I see is 50 watts, driving it with 5 watts. So I thought I would try a different tube. I purchased an 8417 from ebay, when I put the ebay tube in the jb 150 it only produces about 25 watts max. Ok, now for my actual question, there is a small rotatable switch on the back, I'm assuming it's for the bias, plate or tune?? Does that need to be changed due to a different tube being used? Is anyone familiar with this little thing? Any help would be appreciated Maybe I just got a crap tune from ebay.
Thanks,
James, KD9BQO
Thanks,
James, KD9BQO