[R-390] Tubes new or used?

[Llgpt at aol.com]

Somewhere in my dusty files I have a letter from Chuck Teeters, the former  
Director of Radio for the Signal Corps at Ft. Monmouth. He stated what Bill 
said  about iron wire and hydrogen. They knew at that time that shelf life 
wouldn't be  forever............however long that is.
 
I gave up ballast tubes a long time ago, like cigarettes, neither one does  
you any good and they are too damn expensive.
 
Les Locklear
 
 
In a message dated 2/2/2005 8:11:27 AM Central Standard Time,  
chacuff at cableone.net writes:

I guess  I missed most of that past discussion...but I certainly wouldn't 
want any  tube of mine to be full of Hydrogen.  If the filament were to arc  
when it decided to open up I would expect an explosion.  Sounds like  the 
Hindenburg (spelling) all over again.  Are you sure it was  Hydrogen?  Maybe 
Nitrogen...

Just seems strange to me.   Also if it escapes what does it leave behind?

You are also saying that  Ballast tubes have a shelf life.....anybody know 
how long that might  be?

Or maybe I have fallen off into a trap  here.....hmmm

Cecil...
----- Original Message ----- 
From: "Bill  Hawkins" <bill at iaxs.net>
To: "R-390 HF Receiver List"  <r-390 at mailman.qth.net>
Sent: Tuesday, February 01, 2005 10:35  PM
Subject: RE: [R-390] Tubes new or used?


> There's New Old  Stock, which may be 40 years old.
>
> IIRC, in one of our frequent  ballast threads, it came out that
> the iron resistor in a ballast tube  is cooled by hydrogen. Now,
> hydrogen, being the smallest atom, tends  to escape from anything
> made of bigger atoms, which is everything  including glass.
>
> So you need to be careful when you ask about  "new" tubes. NOS
> isn't necessarily what you're looking  for.
>
> Oh, and hydrogen makes iron brittle over  time.
>
> Just to kick over the can, unless you run your receivers  from
> poorly regulated field generators, you don't need a ballast  tube.
> And you don't need the heaters unless you alternate  between
> desert and polar regions with the same receiver. But if the  set
> was aligned with ovens on, it needs to be re-aligned with them  off.
> The calibrator oven needs to stay on.
>
>  Regards,
> Bill Hawkins