[Amps] tube flatulence - gettering

[G3rzp at aol.com]

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