02-15-2021, 08:51 PM
It may also be a good idea to try resoldering the pins of the UV199 tubes you have, failed solder joints is a common problem with 201A, and even AC tubes like #24As. I have also heard of people using 3Q5s and 3C5s as substitutes for 199s, with an adapter, since the envelope looks similar at the top end.
Regards
Arran
Regards
Arran