[Amps] Glass tube plate color answers

[Charles Harpole]

Two answers:
1.  Glass tubes are supposed to glow very red hot while putting out big RF for us.  If they are not within 1% of burning out, why have them?*
 
2.  What happens "When you swap positions"  asked below, is that the other person gets to be on top.  Sometimes this is even fun.
 
*Same reasoning as, "if it hasnt fallen down, it was not high enuf nor big enuf."   Amps, Antennas and hams need to live large or stay in their mouse holes.

Charles Harpole k4vud at hotmail.com 


 
> From: wlfuqu00 at uky.edu
> To: barrie at centric.net; amps at contesting.com
> Date: Sun, 15 Aug 2010 13:10:42 -0400
> Subject: Re: [Amps] Glass tube plate color
> 
> These tubes were never intended to be used as amplifier but in stripline oscillators, either single tube or push-pull.
> There were no real efforts to match them. In oscillators you want low mu so that they will draw lots of plate current to 
> get started quickly. I seem to recall the plate dissipation was 200 Watts with a very bright glow. These tubes were driven hard is early
> radar and radar jammers. Often pulsed. Hams used to use them because they were very cheap on the surplus market.
> EIMAC even made a version with a glass tube attached to it (about 1/2" ID) and no vacuum inside to be used as a ion vacuum guage tube. 
> 
> 73
> Bill 
> ________________________________________
> From: amps-bounces at contesting.com [amps-bounces at contesting.com] On Behalf Of Barrie Smith [barrie at centric.net]
> Sent: Sunday, August 15, 2010 12:52 PM
> To: amps at contesting.com
> Subject: Re: [Amps] Glass tube plate color
> 
> Damit, Carl, that's a good question! I'll try that right away.
> 
> Barrie
> 
> ----- Original Message -----
> From: "Carl" <km1h at jeremy.mv.com>
> To: "Barrie Smith" <barrie at centric.net>; <amps at contesting.com>
> Sent: Sunday, August 15, 2010 10:45 AM
> Subject: Re: [Amps] Glass tube plate color
> 
> 
> > What happens when you swap positions?
> >
> > Carl
> >
> >
> > ----- Original Message -----
> > From: "Barrie Smith" <barrie at centric.net>
> > To: <amps at contesting.com>
> > Sent: Sunday, August 15, 2010 11:55 AM
> > Subject: [Amps] Glass tube plate color
> >
> >
> >> Speaking of class C, I have just completed a nostalgia rig using a
> >> push-pull pair of VT-127As (somewhat similar to the 100TL, but looks like
> >> a spaceman with grid and plate pins sticking out the sides).
> >>
> >> I've been bench-testing it the last few days with a wimpy power supply.
> >> Surprisingly, I'm up to 500 wattts out with 1300 volts on the plates.
> >>
> >> I have several tubes, and have tried a couple of different pairs. In
> >> both instances I've noticed that one tube will have a slightly brighter
> >> plate glow than the other.
> >>
> >> I'd like to have the tubes as closely matched as possible.
> >>
> >> My question is: Which tube is most likely to be the better, the bright
> >> one, or the cooler one?
> >>
> >> 73,
> >> Barrie, W7ALW, DN36au,
> >> QRV 6M, 432 & 1296 EME
> >> _______________________________________________
> >> Amps mailing list
> >> Amps at contesting.com
> >> http://lists.contesting.com/mailman/listinfo/amps
> >
> >
> >
> 
> 
> 
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