Rich is a master at misquoting people.
I plainly stated that I had trouble getting the tube to oscillate at
VHF and couldn't make it oscillate until I removed one or two
ground leads from the grid pins.
Then I watched the tube oscillate, and let it oscillate for several
minutes, without a single arc or big bang. The tube drew grid
current, and anode current, I could move the current higher and
lower by moving the tuning cap, but no problems other than anode
heat from the current.
My results closely parallel the ones you quote below Ian.
Date sent: Sat, 5 Jun 1999 23:33:51 +0100
To: amps@contesting.com
From: "Ian White, G3SEK" <G3SEK@ifwtech.demon.co.uk>
Subject: Re: [AMPS] TL-922 Filament Transformer Protection
>
> Picking up one of Rich's points:
>
> >? As I recall, during the grate parasitics debate you stated that you
> >were able to make an AL-80 oscillate at c. 155MHz. . Dick Erhorn claims
> >that no Alpha has never sustained a parasitic-oscillation -- even though
> >he has reportedly seen plenty of gold-sputtered tubes.
>
> Here's part of a message sent to me some months ago, by someone who reads
> these debates but chooses not to take part publicly -
>
> >>I did a number of commercial amplifier designs in broadcasting and MRI
> >>(including many years of experience with YC-156 at 20kW pulse) and saw
> >>lots of parasitics. But never once did I see a parasitic cause damage.
> >>We even once ran a test amplifier under load with a parasitic singing
> >>along for several weeks. It was a pair of 8877s in parallel, operating
> >>freq was 88MHz, and the parasitic was 220MHz. We needed to test the
> >>ruggedness of the amp, but we couldn't tame the parasitic at the time we
> >>were scheduled to start the "abuse test", so we just went into the test
> >>with one prototype and worked on the parasitic issue on the other
> >>prototype. No boiled off gold, etc.
>
> (Quoted with permission, of course. The original author is not anybody
> whose name I've ever seen mentioned in debate.)
>
> 73 from Ian G3SEK Editor, 'The VHF/UHF DX Book'
> 'In Practice' columnist for RadCom (RSGB)
> http://www.ifwtech.demon.co.uk/g3sek
>
> --
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>
>
73, Tom W8JI
w8ji@contesting.com
--
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