Anybody remember tubes? Haha. Anyway this is a new old stock RCA tube. They haven't made these in the USA for a very long time. They are getting rarer and more valuable as time passes. There are a few factories in China and Russia making new ones. The new ones work but are not even close to quality of the old ones. This is a common rectifier tube in old small guitar amps. It is used in the conversion of alternating current into direct current. It's more complicated than just that but I'm not going to try to explain basic electronics especially now in this era of computers and technology. (I couldn't even if I wanted to) Lol.
Here's Neil Young Talking about guitars and amps. He mentions his Fender tweed deluxe amp around 4:30, that amp uses this type of rectifier tube.
