It was hard to get this into the house without being noticed. In the checkbook I wrote "$1.75--Used Radio." Then I took out the power unit to lighten the load, and I put the whole radio in a Home Depot bag and carried it up the stairs very quietly.
The tubes currently in the set are one Tung-Sol TSX199, two Radiotron X99's, and four Tung-Sol 99's.
I have a Heathkit IT-21 tube checker with a 4-pin socket and data for the 99, but I have to ask if it's OK to test a DC tube. The tube requires 3.3V for the filament, but the tube checker data says to set the filament voltage at 2.5. Does 2.5 VAC magically simulate the same current as 3.3 VDC?
Can you believe this? They stamped "RCA" on the rivet heads!
Something else I haven't seen before--a craftsman's tool mark on the cabinet. This might be upside-down or sideways. I think it's supposed to be a gingerbread man.
So, should I try checking the tubes with the Heathkit? I've ordered a '20' to replace the missing UX120.