[Amps] "Tubes 201" - How Vacuum Tubes Really Work

[Bill Fuqua]

I have a 2000T that I hope to use some day. It is the largest vacuum Glass 
tube I have seen.
It will be interesting to see how much gas is in it or not in it.

73
Bill wa4lav


At 01:58 PM 7/24/2006 -0700, Gary Smith wrote:
>As the man sez "I have no dog in this fight" so, no input from me on this
>issue.
>
>But... emails such as this is another reason why I subscribe to this group.
>Give and take (+++ &  - - -) and so-on.  I have learned so much by reading
>the missives (and ratings) from the members of this forum, from their varied
>options, experiences along with the unbelievable storehouse of knowledge
>that exists within the group.   And yes, I will stay tuned.  I need yet more
>education in the world of QRO and such.
>
>73,
>
>Gary...wa6fgi
>
>
>----- Original Message -----
>From: "Will Matney" <craxd1 at verizon.net>
>To: <amps at contesting.com>
>Sent: Monday, July 24, 2006 9:46 AM
>Subject: Re: [Amps] "Tubes 201" - How Vacuum Tubes Really Work
>
>
>On 7/24/06 at 6:25 AM R L Measures wrote:
>
> >On Jul 23, 2006, at 10:40 PM, Peter Chadwick wrote:
> >
> >> Rich said:
> >>
> >> >I autopsy tubes, and I have no yet seen an arc mark in a kaput tube
> >> with a good vacuum.<
> >>
> >> It's sad that G6JP is no longer alive. He spent his entire working
> >> life doing tube manufacture and applications at the M-O valve
> >> company, and he said that flashovers weren't uncommon.
> >
> >Surely, and those valves that had leaky seals and flashed over, did
> >not pass final test, landed in the recycling bin, and never saw
> >daylight.
> >> There's also the articles in the Journal of the IEE. My father in
> >> law tells me that they had flashovers in continously pumped tubes
> >> at the QRO point to point stations he worked at -although the
> >> biggest problem was when someone with greasy fingers touched the
> >> grid during re-assembly. That meant that they had a lot of pumping
> >> to do before the valve really got hard.
> >>
> >> So Mr. Measures, the fact you've never seen what you take to be
> >> marks of a flashover in a  tube with good vacuum doesn't mean that
> >> it doesn't occur.
> >Agreed. However, there's presently a faint smell of specious
> >reasoning in the air.
> >> But, of course, proving (or disproving) a negative is not easy, so
> >> either party can sit back in the warm glow of satisfaction that
> >> really, they're the ones who are right!
> >
> >Are Au and Mo notable emitters?
> >Can the grid of a tube with a hard vacuum reach high temperatures if
> >no current is passing through it?
> >If zirconium has to be at 1400ºC (Terman) in order to absorb oxygen
> >and nitrogen, how can a 3-500Z's anode getter air molecules?
>
>
>One needs to study how tubes are constructed to see what may happen. The
>metals used in them were picked
>over their high heat qualities (wouldn't melt). The plating had to do with
>emission of electrons.
>
>Yes, I seen a reference earlier about the 3-500Z having a getter of
>zirconium. For it to work, it's optimum temp is
>1400 deg C and is what it's ran at in this application. In that case, the
>anode would be white hot (the welding color of steel). There's some other
>problems with this too, but I won't go into them here (IE Hydrogen gas). If
>one actually
>wanted to make this work, it looks like a tantulum anode would have been a
>better choice.
>
>
> >
> >Editorial -- As I see it, the proponents of the floating grid
> >catastrophe theorem have a conflict between reality and what they
> >wish reality to be.
>
>
>The theory is what has me bothered in that, if I read them right, think a
>grid could become positive from an arc. Also, in the ways a grid could
>become positive. A good read of the book, Radio Engineers Handbook, by
>Terman will straighten out all the mis-conceptions. Actually, Tubes 201
>follows right along with it.
>
> >
> >cheers, Peter
> >> 73
> >>
> >> Peter G3RZP
> >
> >R L MEASURES, AG6K. 805-386-3734
> >r at somis.org
>
>Best,
>
>Will
>
>_______________________________________________
>Amps mailing list
>Amps at contesting.com
>http://lists.contesting.com/mailman/listinfo/amps
>
>
>_______________________________________________
>Amps mailing list
>Amps at contesting.com
>http://lists.contesting.com/mailman/listinfo/amps