Re: Vacuum Tubes

To: tesla-at-pupman-dot-com
Subject: Re: Vacuum Tubes
From: "Stephen G. Stanton" <ulflyer-at-i-cafe-dot-net> (by way of Terry Fritz <terryf-at-verinet-dot-com>)
Date: Fri, 16 Oct 1998 18:31:33 -0600
Approved: terryf-at-verinet-dot-com

Ben:  I would reconsider using the 304s for your coil unless you can get
them free.  Sockets for them are getting very hard to come by.  Also, each
tube requires 10 v at 12 A to light it up (you could wire each one in
parallel but that would require 5 v at 25 A, a huge transformer!!.  That's
a lot of power just to light filaments.  You'd do better to fish around for
a used 833A from a local a.m. radio station; they are used in the finals
and modulators, and often can be had for the asking.  If you had to buy
one, it's still less money than a USED 304TL.  RF Parts in California sells
a socket, and the grid and plate connectors for it, costly, but easier to
find than that same stuff for the 304TLs.

There have been postings on this list containing the circuit for a
parallel-833 coil.  You might check the archives for several months back...

I built a rf amplifier and modulator for my a.m. "California KW" ham
station.  It uses a single 833A in the final modulated by push-pull 304TLs.
 I lucked out and found an old rf deck which used the 304s and thus I had
the sockets and heater transformers.  The whole rig makes a lot of pretty
light when it's fired up.  It was my "dream" rig when I was a teenager back
in the '50s.  Now it's "for real"!

Good luck,
Stephen, KJ6LH