Altho' I've not had any major problems with 572B's , I am curious about the
the QB-4/1100 mentioned here as a replacement . what are the spec's on this
tube, where is it available, and how much would it cost me??? Is it really
any better as far as stability, life , etc. I'm always interested in a
better way if it exists. thanks.!! 73
carl / kz5ca (are major mods. needed to use this tube???)
----- Original Message -----
From: "Peter Frenning, OZ1PIF" <oz1pif@get2net.dk>
To: "Osten B Magnusson" <sm5dqc@algonet.se>; <amps@contesting.com>
Sent: Tuesday, August 21, 2001 2:17 AM
Subject: Re: [AMPS] 572B and an old FL2000B
>
> Hi Osten,
> Yes it does, what it is actually about is not the bias per se, but the
> cut-off voltage, which has to be higher (more negative!) for the more
lively
> Svetlana tube. I do not recommend you to use the this tube, I went through
> two sets in fairly rapid succession, before I threw the towel in the ring.
> My FL2000B is now happily clicking along with a single QB-4/1100, giving
> some 600W+ on the lower bands, and about 500W on 10m, something that it
> never could manage with the 572Bs, and being absolutely 100% stable and
easy
> to tune.
>
> IMHO the 572B is totally unsuitable for RF amplification (at least as far
as
> the Svetlana version is concerned), it is far too temperamental and prone
to
> take off on its own, instanstantly destroying the tube(s).
>
> If this discourages you from keeping the FL2000B, don't despair, I'm
looking
> for one more, which I want to convert into a 50MHz amp, using two
QB-3/300!
>
> Vy 73 de OZ1PIF, Peter
>
>
> New DXpedition to Greenland for CQWW! See: http://www.qsl.net/xp1ab
>
> ********** OZ1PIF **************
> email: oz1pif(no-spam-filler)@get2net.dk
> http://hjem.get2net.dk/oz1pif
> Shack Ph. +45 4619 3208
> Snailmail:
> Peter Frenning
> Ternevej 23
> DK-4130 Viby Sj.
> Denmark
> ***********************************
> ----- Original Message -----
> From: "Osten B Magnusson" <sm5dqc@algonet.se>
> To: <amps@contesting.com>
> Sent: Tuesday, August 21, 2001 12:41 AM
> Subject: [AMPS] 572B and an old FL2000B
>
>
> >
> >
> > Hello friends!
> >
> > I know that some of the Yaesu amplifiers, FL2100B etc
> > need another bias supply when using Svetlana 572B's,
> > but does this apply to the very old FL2000B also? This
> > amplifier is not mentioned in this respect on the Svetlana
> > web-site, the USA-site that is.
> >
> > 73 and thanks in advance de Osten / SM5DQC
> >
> >
> >
> > --
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> >
>
>
>
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>
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