[Amps] Re: Voodoo "EMF' forces from grid current pulses

[Steven Grant W4IIV]

 2 <2 at vc.net> wrote:


>I have just spent an entire semester working on electro magnetism and the
>physics is VERY fresh in my mind. Eric's calculations are sound, I am sorry
>Rich but you are way off the mark here, there is no way that sufficient
>magnetic flux could have been generated in the scenario you describe.
>Certainly nowhere near enough to distort the grid wires as you have
>suggested.
>

the thing you fail to see here is that there is parasitic current flowing here.

it cannot be running in the tank circuit cause it is blocked there, so it is either jumping gaps to complete its curcuit, or it is flowing in the grid.

dont forget---wherever there is current, there is magnetic flux


>I suggest that you re-think this one. I can quote some equations at you if
>you wish.
>
** I need some measurements during the big-bang that preceeded a 
grid-fil short. 


## try greater than 800 ma (the limit of my meter)
>Regards
>
>Conrad G0RUZ
>
>-----Original Message-----
>From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com]On
>Behalf Of Ian White, G3SEK
>Sent: 04 February 2003 14:54
>To: amps at contesting.com
>Subject: Re: [Amps] Re: Voodoo "EMF' forces from grid current pulses
>
>
>2 wrote:
>>The grid wires in all of the shorted 3-500Z and 3-400Z tubes that I
>>have autopsied appear to be straight. I have never seen a bent grid.
>>The bent element is the thoriated-tungsten filament helix.
>>
>>>you will have to come up with another mechanism, one that can generate
>some
>>REAL
>>>force.
>>>
>>There is no doubt that real force did the bending because real force is
>>required to bend a bent filament straight. It typically takes 11-G for
>>c. 40-seconds, with the filament operating at c. 5.6V, to straighten
>>the
>>filament.
>
>Fine - so where *did* the force come from that bent it? Eric has just
>shown that the EM force between two parallel wires is about 1/1000 of an
>ounce for the conditions he assumed (two 1in wires separated by 1mm,
>each carrying 10A). Even if you dispute the value of the current, you're
>still adrift by several orders of magnitude.
>
>>- Eric -- How do you explain:
>>1. the grid-filament short often seen in 3-500Zs often follows a
>>big-bang?
>
>And just before the event, the grid and filament were already how close?
>Nobody knows, because only totally dead tubes are ever autopsied.
>
>>2. the simultaneous burnout of a grid choke made from 28ga Cu wire?
>>
>That shows that considerable grid current had flowed - but nothing more.
>You still don't know whether the blown choke and the grid-filament short
>were both caused by the "main event" at the same time; or whether that
>event only caused the grid-filament short, which then blew the choke as
>a follow-on.
>
>Also there is conflicting evidence. On the one hand, enough grid current
>has flowed (somehow) to burn out the choke. On the other hand, it's not
>the grid that has bent - it's the filament.
>
>
>I'm sorry, but the evidence about this whole topic certainly does *not*
>"speak for itself"... at least, I can't hear the voices :-)
>
>We're back again to the limitations of autopsy evidence, and the need to
>sometimes return an Open Verdict.
>
>
>--
>73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
> Editor, 'The VHF/UHF DX Book'
>http://www.ifwtech.co.uk/g3sek
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>
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- R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K, 
www.vcnet.com/measures. 
end


Steven Grant W4IIV

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STEVEN GRANT    W4IIV



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