Rich Measures wrote:
>Funny thing that the alleged Rauchian gas disappears by the time that the
>kaput tubes are removed from the amplifier and tested with a
>high-potential tester.
Removal of gas can occur by several physical and chemical 'scavenging'
processes that may take place on timescales of seconds to hours.
A sudden, small release of gas could cause an arc because the
scavenging process is too slow; but after several hours/days it's quite
feasible that the gas would have gone.
> I tested a pair of kaput 3-500Zs for Rod, W7OM,
>this morning. Both appeared to have been damaged by VHF parasitic
>oscillations. However, the vacuums tested good.
A high-pot test of a tube that's still red-hot out of an arced amplifier
would be more relevant - though admittedly much more difficult -
followed by a timed series of similar tests over several hours or days.
> At least one of the two
>appeared to have a bent filament--like the one on page 15 in the Sept.
>1990 *QST* article "Parasitics Revisited".
The photograph is convincing, but what exactly is generating the force
that bends the filament? Please can somebody provide a *fully detailed*
explanation that fits the facts - ALL the facts, Ma'am :-)
73 from Ian G3SEK Editor, 'The VHF/UHF DX Book'
'In Practice' columnist for RadCom (RSGB)
www.ifwtech.demon.co.uk/g3sek
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