Well,
I'll chime in on this one with personal experience.
Regardless of whether you believe in the "Myths" or not.
Most are not supported with facts.
I have a Clipperton-L purchased new in 1980. It is in daily
use and still has the four original 572B tubes. It is
original and does not have any form of slow start. Also
the four tubes are even mounted in a horizontal position.
I assume the inductance of the transformer has some control
of the in-rush current. I do know these tubes do not exhibit
any visible form of high light intensity when first turned on.
Based on the "Myths" perhaps someone could compute and tell me
when one of them might have a filament failure?
73s de Jim
W5IFP
> -----Original Message-----
> From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com]On
> Behalf Of Carl
> Sent: Friday, June 15, 2012 8:11 AM
> To: amps@contesting.com; Bill Fuqua
> Subject: Re: [Amps] filament instant heating query
>
>
> Amen to that.
>
> There seems to be more belief of myths recently in the ham
> field than before
> and I suspect a good part is from AG6K's absolute pathetic
> nomsense that is
> read by the totally uninformed and it becomes doctrine.
>
> Carl
> KM1H
>
>
> ----- Original Message -----
> From: "Bill Fuqua" <wlfuqu00@uky.edu>
> To: "Charles Harpole" <k4vud@hotmail.com>;
> <amps@contesting.com>; "David
> Springer" <dspringer@cfl.rr.com>
> Sent: Friday, June 15, 2012 12:49 AM
> Subject: Re: [Amps] filament instant heating query
>
>
> > Myth Busters did an experiment with light bulbs to see how they were
> > affected by switching some on and off and others left on.
> > Practically no difference.
> > I believe this mostly started with light bulbs because when once the
> > filament gets so thin at some point due to the evaporation of the
> > tungsten the next time you turn it on and you have a surge of
> current in
> > the lamp it burns into. This thin area has a higher resistance
> > than the rest of the filament and gets hotter.
> > I don' think there is any real rocket science, molecular physics or
> > quantum mechanics to it.
> > 73
> > Bill wa4lav
> >
> >
> > At 03:59 AM 6/15/2012 +0000, Charles Harpole wrote:
> >
> >>to check on a supposition............
> >>
> >>
> >>
> >>It appears possible that the sudden application of voltage to a tube
> >>filament causes degradation of the filament.
> >>
> >>
> >>
> >>What seems to happen? Is it possible that the very rapid heating of a
> >>filament could cause so much quick molecular action (rapid increased
> >>bouncing around of the molecules) that the shape of the
> filament could be
> >>changed? A deformed filament could then be too close to
> other components
> >>to cause an arc, perhaps?
> >>
> >>
> >>
> >>Or is the action on the atomic level...i.e., does heat change
> the actions
> >>of electrons in an atom?
> >>
> >>
> >>
> >>But, maybe the filament rapid heating works just fine, and all of the
> >>"slow start" "inrush protection" circuits are a waste?
> >>
> >>
> >>
> >>Another inquiring mind wants to know.
> >>
> >>73,
> >>
> >>Charles Harpole
> >>k4vud@hotmail.com
> >>_______________________________________________
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> >
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> >
> > -----
> > No virus found in this message.
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> > Version: 10.0.1424 / Virus Database: 2433/5070 - Release
> Date: 06/14/12
> >
>
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