Experiences with 3DG4s?

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Folks,
I was rummaging around the "whatever" tubes in the attic and again noticed the 3DG4s - really hadn't paid much attention to these bottles since I worked on TVs in the early 70s. But checking out the specs I noticed that they have greater current capacity than 5U4GBs with lower voltage drop. But they have that 3.3 volt filament at 3.8 amps. Hmmm, but that's only 0.8 A more than a 5U4 and I suspect that some trannies are robust enough to pull that extra current so you could wire a socket with pins 4&5 tied, pins 6&7 tied, pins 1&8 tied with a 0.45/10W resistor between pins 2&3 creating a socket that would, with sufficient filament current, accomodate the 3DG4 or a 5 volt rectifier.
Aha, of course there is a "rub" - my manuals state that pin 2 is "internally connected" - but to what? The four valves I've got have a thick internal wire going from pin 2 to the bottom mica and ending there unconnected. Does anyone have any idea why this is or why it would prevent a dual tube/voltage socket?
Rob

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Topic - Experiences with 3DG4s? - Rob Mercure 16:38:32 08/04/06 (1)

Re: Experiences with 3DG4s? - Swanson 10:37:42 08/12/06 (0)

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