MaCo 200 Amplifier

The biggest issue with grounding the grids through RF chokes is the possibility of the choke overheating and opening up. when this happens, the tube is destroyed (regardless of whether it was failing to begin with, or not). This 'event' can also do a lot of "chain reaction" damage, such as plate transformer, metering, rectifier and/or other meltdowns. The reason some manufacturers use chokes while others directly-ground them, is because there are two totally opposed opinions by their designers.

There are absolute VOLUMES of such opinion pieces to be found online, in several forum threads on Eham, QRZ and others on this topic. they're usually littered with 'flames' flying back n forth from both schools of GG amp design.

Personally, I'm of the "directly-grounding them" school, while installing a nice, fat glitch resistor in the event of a tube's arc-over..... But that's just me. And while I refuse to join any of those debates about it (ever again because I know my own melting point), it's really "no big whoop" either way IMHO.

I recommend against it. The tube's anode current with zero drive will be high enough to overheat most sweep tubes. Grounding the control grid with a 1k resistor and a disc bypass cap makes the grid grounded for RF currents but allows you to put negative 8 or so Volts DC on the grid. This prevents it from overheating if you turn the radio's carrier power too low, or use sideband.

73