RE: 4 Grids

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Rich" <rdjmgmt-at-socket-dot-net> 

Thanks Steve, that is what I thought. I will call it my test and set up
tube because I don't really know what I am doing with tubes and this
will be my first tube coil. I am starting with a single tube. I need to
wind a 5v transformer anyway because I have another triode (8283) that
needs 5v at 30amp and the biggest 5v I have is 22amp.
  The 304 tube looked odd because at 10v setup with reduced input one
side looked normal, two lit dim , the other side, one no light , one
bright.
I tried a second tube and all four look good at up to 1/2 voltage.

Rich

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Sunday, October 03, 2004 6:46 PM
To: tesla-at-pupman-dot-com
Subject: Re: 4 Grids

Original poster: "Steve Ward" <steve.ward-at-gmail-dot-com>

I have run across many partially dead 304TLs.  I did in fact run 1/2
of the tube in a VTTC circuit.  I think the most i got was about a 12"
spark and the plate was very cherry red.   I didnt care about the tube
so i didnt mind how hot the plate was getting.

Anyway, im not sure if you can actually run just 3 of the filaments,
unless somehow the 4th was shorted out?  From what i remember, they
wired the filaments in strings of 2, and there is no center tap
between each single filament, but there is between all 4.  So you
could either series all 4 filaments at 10V, or you could parallel 2
strings of 2 at 5V.  Anyway, it may be worth your time to just play
around with half the tube, its probably not good for anything else.

Steve


On Sun, 03 Oct 2004 14:46:43 -0600, Tesla list <tesla-at-pupman-dot-com> wrote:
  > Original poster: "Rich" <rdjmgmt-at-socket-dot-net>
  >
  > I was bringing a 304tl up to operating voltage on the filaments.
Well I
  > guess they call the 304 for a reason, 3 for triode and 4 for the 4
  > filaments. One tube has one bad filament. I have the tube set up on a
  > series circuit because my main filament transformer is 10v. I found
out
  > quickly I can't run it that way. One filament will pull to much
  > voltage.  Before I junk the tube, I could wind another 5v trans, has
any
  > one ever run one with just three of the filaments.
  >
  > Rich
  >
  >