>OK,
>
>Thanks to those who responded to my seemingly dumb question about why no
>carbonization marks exist around tubes which supposedly had an arc-over
>in them. Specifically this is in regards to the bent filament helix
>phenomena in the 3-500Z's.
>
>So here's a follow up question:
>
>Several people pointed out that you wouldn't get carbon scoring from an
>arc because the tube is evacuated and therefore there is nothing that
>would cause carbonization (OK, maybe that's not the scientific
>explanation, but you know what I mean).
-- i.e., arc cratering does not involve carbon.
>However, if there were no gas of
>any kind inside the tube, then how did the arc occur? Doesn't an arc
>occur when the voltage potential across a gas is so large that the
>molecules in the gas break down, turn into a plasma and thereby creat a
>low resistance path for current to flow?
electrons are temporarily ripped off.
>If there is no gas then why is
>one theory called the Gas Discharge Theory or whatever? If there IS some
>sort of gas, then isn't it possible that carbonization could occur due to
>the arc? Or is it the wrong type of gas (ie: needs to contain carbon)?
>
Oxygen gas and/or nitrogen gas become conductors when enough potential
gradient exists to free their electrons. In a partial vacuum, relatively
low potentials are needed to accomplish this and create an arc.
>........
cheers
Rich...
R. L. Measures, 805-386-3734, AG6K
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|