[Amps] tube flatulence - gettering

[Peter Frenning, OZ1PIF]

Back in the early 60's, I homebrewed an 2xEL84 LF amplifier running some 
450V on the anode - way way over spec as I remember (just looked it up: 300V 
max producing 17W/tube in class B), to produce some 50 or 60W output (I'm 
somewhat hazy about this figure now, some 40+ years later), what I do 
remember clearly is the blue light emanating from the tubes, pulsating in 
sync with the output - also that tubes only took this for about a year 
before having to be replaced (that may have been due to Bill Haley and other 
Rock'nRoll bands though)

Vy 73 de OZ1PIF, Peter

**********  OZ1PIF **************
email: oz1pif(no-spam-filler)@privat.dk
http://home24.inet.tele.dk/oz1pif/
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Snailmail:
Peter Frenning
Ternevej 23
DK-4130 Viby Sj.
Denmark
***********************************
----- Original Message ----- 
From: <G3rzp at aol.com>
To: <craxd1 at ezwv.com>; <amps at contesting.com>
Sent: Friday, November 19, 2004 7:46 PM
Subject: Re: [Amps] tube flatulence - gettering


> I've seen receiving tubes ( power tubes - 6V6 size) with perfectly silver
> getter coating on the glass, but a blue glow between the electrodes with 
> volts
> on - a sure sign of gassiness.
>
> I've also seen a lot of 826/829/832 series tubes with enough air inside 
> that
> the filaments won't get red, Which is why I wouldn't touch any of them 
> that
> people ask funny prices for. After all, many of them were made for WW2, 
> and
> weren't expected to have much of an operational life.
>
> 73
>
> Peter G3RZP
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