Fw: [Amps] Conditioning Spare Tubes After Storage

[skipp isaham]

Hi Jeff, 
-
I've received some broadcast transmitter tubes with 
recommended warm up times of 10 plus min, some 
as high as 30 minutes min. 
- 
A fellow broadcaster (now an SK) never paid 
much attention to the pre power warm up time 
especially the first install. 
-
He called me over one night to source a 
breaker trip problem which was traced back 
to the tube, which was not allowed the 
recommended pre start filament idle time.
-
After 30 min, I applied power and the everything 
worked as expected, the transmitter was back 
on the air. 
The program director went back to defcon 
level 3 spazz level (some of you broadcasters 
can appreciate that remark). 
-
>From memory, Econco was our rebuilt tube 
supplier of choice (great people), the pentode 
with handles was one of the more fussy 
animals (5cx1500a) and of course I was 
working on the first Sparta 602/680 off the 
assembly line. 
-
20 to 30 min of warm up time is relatively 
cheap. I believe the recommended warm up 
time was mentioned in the Econco paper 
work, although I do it as a rule of thumb. 
- 
Interested parties could call Econco 
in Woodland, CA if they wanted more 
detailed information. 
-
cheers
skipp 
- 
--------- Forwarded message ----------
From: "Jeff Maass" <jmaass at columbus.rr.com>
To: "Amps Mailing List" <amps at contesting.com>


I have a pair of 4CX800A tubes that have been on
the shelf here for a few years (and for an unknown
period before I got them). I'm about to swap them
into one of my Alpha 91b amps.

Is there a recommendation to let these tubes run 
without HV for a period before pressing them into
full service? 

I did a search of the archives, and it seems that 
there is no consensus on the need for this procedure 
for any but the largest "tubes with handles".

73,

  Jeff Maass  K8ND

  


________________________________________________________________
The best thing to hit the internet in years - Juno SpeedBand!
Surf the web up to FIVE TIMES FASTER!
Only $14.95/ month - visit www.juno.com to sign up today!