[Amps] General question on filament life

[Gary Myers]

BINGO!

thanks.

g.


----- Original Message ----- 
From: <pegasus at mho.net>
To: "Phil Clements" <philc at texascellnet.com>
Cc: "'Gary Myers'" <garymyers at powerc.net>; <w9ac at arrl.net>
Sent: Thursday, February 08, 2007 11:28 PM
Subject: Re: [Amps] General question on filament life


:
: > I have 2 amps here; one is "instant-on" and one has a 4 
minute delay at
: > start-up. The latter is turned on every time I turn on my 
transceiver. I
: > don't think of it as a separate "accessory." I use it for 
every QSO I
: > make.
: > I have too much respect for my fellow operators. I try to 
supply them with
: > the best possible signal so they won't have to listen to 
noise and fading.
: > I
: > too have missed some juicy DX in the past waiting for the 
amp to warm up!
: >
: > (((73)))
: > Phil, K5PC
:
: Hello Phil, et al,
:   I've had several lengthy conversations with Reid Brandon, 
chief
: applications engineer for Eimac regarding filamant life and 
tube
: health.  We have discussed how power tubes last tens of 
thousands of
: hours in commercial service, yet often a small fraction of 
that in
: amateur service despite the fact that they aren't generally 
worked as
: hard.  After investigating the operating habits of hams with 
high
: failure rates he's found that they very often have operating 
habits
: that contain several schedules a day where the amp is cycled 
on and off
: each time.   One documented (and extensive) study that is 
cited by
: Eimac  conducted in the commercial environment found that each 
time a
: power tube is turned on it loses about 60 hours of it's 
expected life
: as compared to a constant-on condition.  Some hams can go 
25-30 years
: between tube failures, while others seem to be changing them 
all the
: time.  There are lots of variables, but Reid said the high 
cycle rate
: jumps out as a common condition.
: 73,
: Dennis
: N0SP
: