6EA8 , 6GH8 , 6U8 all compatible?

[kvflyer]

Originally Posted by benman94

I think there's a 4 digit all numerical tube number that is also equivalent. 7199 maybe?

Different pinout...

[Zenith26kc20]

Dynaco amplifier input/driver tube (7199). Expensive! Different pinout (as mentioned), very prone to heater to cathode shorts! Good ones getting scarce!

The better 6GH8 I find are the RCA and GE.
Check new ones before using! I've seen new ones bad. Especially the Asian ones near the end of production. The later RCA TV's devoured many of them.