Hi Les,
Happy New Year,
I am sure that you are aware that this tube is listed as rare.
A couple of things to try. I can not guarantee either and you are on your own, as I have no way to test this but from all the info I could find ——
idea # 1; try a 37 or a 76 in your radio. If it is a model 1721 that you are looking at, the 86 tube is only an audio driver.
idea #2 Alternatively If you have an 86 try testing it as a 37 or 76. They are both triodes and according to what I can find have the same basing layout and heater voltage. You can make sure the heaters are on the same two pins before you start . It would not hurt to check the heater connections.