[Amps] 3-500zgs

[Jason Buchanan]

> Couldn't it be that the graphites are totally different material than the 
> standard Eimacs?

I'm sure that's 99% of it.  Although my old Amperex 8163s will get orange as 
well, it just takes them longer which is why I guessed at it being a thicker 
material.  And likewise it takes quite a while for the exhaust air 
temperature to drop.

But as SM0AOM inferred previously, there's graphites and then there's 
graphites - the older graphites weren't meant to withstand orange the way 
the new graphite design tubes do.  I can't remember where I read about 
that - the term was "graphite poisoning" and perhaps it was Mr. Measures' 
site or thereabouts.  I honestly do not remember.

I've foolishly packed my Amperex 8163s away in packing cartons and replaced 
them with old Eimac 3-400Z tubes for the sole purpose of viewing their glow 
during operation.  I get a comfortable 500W in CW position with dull orange 
color - those tubes aren't up to the task of a sustained KW on SSB position. 
Unfortunately, I don't have enough $$$ to purchase another 7dB so losing the 
glow for another 3 or 4dB won't cut it for me.

Although I will say the Acom 1000 I had was VERY nice.


73 Jason N1SU

-- 
Jason Buchanan - Boxboro, MA  FN42fl
Website: http://n1su.com/