[R-390] Tubes new or used?

[Cecil Acuff]

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
>
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