[NJARC] Type 47 vacuum tube

[john ruccolo]

Hi Nick,

That's not so unusal. Many power pentodes have the
suppressor grid (G3) tied to the cathode. What makes
this a little different is that it's a directly-heated
tube (like a 45, but the 45 is a triode, of course).
So the cathode and the filament are, in effect, the
same element. Take a look at, for example, a 6V6 and
you'll see what I mean. That's an more typical example
with an indirectly-heated cathode.

Hi Gary D. -- I don't mean to step on your toes over
there in the Tube Dept., but I was about to post
something and saw this.

Regards,

JR

--- Nick Senker <ns539 at earthlink.net> wrote:

> Visit our web site - See http://www.njarc.org
> _______________________________________________
> I meant to ask Gary D'Amico about a type 47 tube at
> the clinic.  It is used as an audio output on a
> Philco Mod 70 I am working on.  It does not have a
> conventional cathode (see basing diagram on
> nostalgiaair.org).  Could Gary (or anyone) comment
> on this?  
> Nick Senker
> _______________________________________________
> NJARC mailing list
> NJARC at mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/njarc
> 


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