[Amps] AL80B Tube?

[gdaught6@stanford.edu]

On 4 Mar 2005 at 14:42, R.Measures wrote:

> Hello, Brad -- My guess is that the tube has an intermittent fil-grid
> short since neg grid-I is what typically results when such a short
> occurs.  

I agree.  But the problem MIGHT not be in the tube.  I once 
encountered an amp with exactly these symptoms, but even trying a 
couple of good tubes didn't help.  Eventually, I found a little 
solder whisker or blob at one end of the filament choke that would 
sometimes short (the filament) to the chassis.  A few seconds with 
the slobbering iron cured the problem completely.

Other times it most certainly WAS the tube.  I'm just suggesting 
another place to look.

73,

George T. Daughters, K6GT