Re: Tubes

To: tesla-at-pupman-dot-com
Subject: Re: Tubes
From: FutureT-at-aol-dot-com
Date: Tue, 21 Jan 1997 16:50:44 -0500 (EST)
Subscriber: FutureT-at-aol-dot-com Tue Jan 21 23:10:35 1997

> Stephen,
 
>I am not at all familiar with the nomenclature ECC803S, but I was 
>able to look up a type 803 transmitting tube in the RCA databook.  
 >Although this tube is a pentode, at 2000 volt plate rating and 125 
> watt plate dissipation it is a heck of a lot of tube for $15, 
>assuming of course that what you have found is truly an 803.  If it 
>is, I'd get one and try it.  Tie all three grids together and pretend 
> it is a triode, might work.  The filament on the 803 is 10 volts at 5 
> amps.  The tube has a plate cap and a giant 5 pin base (same as a 
>4-125A/4D21, with a straight sided diameter of 2-9/16" and an overall 
>length of 9-1/4".
 
>snip 
>rwstephens
  >>

Steven, Robert,

I also do not know if the ECC803S is the same tube as an 803.  I used an 803
in a tube coil, (found 3 of them at hamfest for $3 each),  I connected a 15k
resistor from the high voltage supply to the screen grid, and a 45k resistor
from the screen grid to the suppressor grid, the coil gave a 5 to 6" spark.
 By the way,  an 845 tube gave a 7" spark, and a 304TL tube gave a 10" spark
in the same tube coil, which happened to be powered by a microwave oven
transformer.

John Freau