Anyone have any experience with these radios? I searched a little, but didn't come up with much. The unit looks to be in great shape and the seller claims it worked daily for years up until a couple weeks back. Now it doesn't power on. Looks worth giving a shot since I am trying to learn more about tube amp design (mainly instrument, not hifi) and want a small tube set up for my little 9'x8' workshop. Worth $50?