No, that not the new prefix for Whachamakallistan. Does anyone have a spare 12BY7A toob in the junkbox that they are willing to part with? Or know of a local source? I'm trying to resurrect a TR-4 and working my way back in the transmitter chain and that's the next 'suspect'. My junkbox is completely devoid of firefets except for big ceramic ones. 73, Mike N4GU