[Milsurplus] Wanted: 838 Tubes

[Richard Brunner]

John, OM:
The 838 is a high-mu tube, meaning zero volts grid bias for class B
operation.  You could use 211's if you provide about -80 volts grid
bias, or 811A's with about -9 volts grid bias. (at 1500 volts B+)  Don't
forget the 6.3 volt filaments...

You can also use 813's and 803's with all the grids tied together, with
only a few volts bias, and maybe zero bias at only 1250 volts B+.

211's are more plentiful that 838's, but don't look to buy them...

Richard, AA1P

On Mon, 2010-03-15 at 15:24 -0700, J. Forster wrote:
> The Battleship Massachusetts is getting its 1MC (PA System operating) and
> needs some 838 tubes.
> 
> Unfortunately, these seem to be highly coveted by the Audiophools for
> their nutty triode amps, so are hard to get.
> 
> If anybody has any, please drop me a note off-list.
> 
> Also, I've thought about making a plug-in substitute from either a more
> plentiful tube, or even from VMOS transistors.
> 
> Does anybody have thoughts on this approach. Response from DC to X-Band is
> NOT a requirement as with the "golden ears" crowd.
> 
> Best,
> -John