Heh,
I still have a few 250TH and have a 750TH in good shape & one that
looks as new but has a popped filament. Never did use either of them.
That 750TH is a monster.
Gary
KA1J
> My first big amp was PP 250TH's in 1957. I had them a bright orange a
> few times. Went to the 4 x 1's a decade later when freebie BCB pulls
> were everywhere around here, built my last one in the late 80's.
>
> Now have amps with 250TH's and 304TL's for my return to AM. Those TL's
> throw out so much light you can read a book.
>
> http://groups.yahoo.com/group/glowbugradio/?yguid=347629384
>
> Still looking for a couple of good 861's.
>
> Carl
> KM1H
>
>
>
> ----- Original Message -----
> From: "Gary Smith" <Gary@doctorgary.net>
> To: <amps@contesting.com>
> Sent: Wednesday, November 12, 2008 6:47 PM
> Subject: Re: [Amps] help with corona discharge
>
>
> >I personally miss the tube glow from the first amp I built. It had
> > that beautiful 4PR1000A with 6KV on the plate.
> >
> > That glow was a thing of beauty.
> >
> > Gary
> > KA1J
> >
> >> Every Commander amp that I have added QSK and vacuum relays to has
> >> had the blue glow when looking through the cooling fins..
> >>
> >> The three holer on my desk, with brand new 3cpx800 tubes, glows
> >> blue. The ten year old 3cx800 tubes also glow blue.
> >>
> >> The tubes are full output, and there is no issue. I believe the
> >> glow which appears when cut off bias is removed, may be dependant
> >> upon the trace elements in the ceramic, with different types of
> >> ceramic producing somewhat different colors.
> >>
> >> Your amp is fine, you don't need to worry, just operate.
> >>
> >> 73,
> >>
> >> Mike
> >> W2AJI
> >
> > _______________________________________________
> > Amps mailing list
> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
> >
>
>
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