...none of which addresses the question asked!
He's **buying** an amp, not building.
He wants to know about the likely continued **availability**
of the 3CX1200A7, 8877, and 4CX800A, not alternatives that
may be better designed.
My guess is that when the cockroaches inherit the World,
they'll nest in the shelves of NOS 4CX800A tubes cranked
out by Svetlana over the past and future years for the
Russian military, industrial, and the Amateur market.
They're very available now, and cheap due to their supply.
The 3CX1200 series is (A7, U7, Z7) are much more limited in
market, and I'd hope they don't go the way of the 4CX1600B.
It was also designed primarily for the Amateur market,
and is now essentially unavailable just 5-10 years later.
Many unhappy Ten Tec Titan II owners!
There are lots of 8877 out there, by virtue of their long
production, and their use in commercial/industrial
applications. At least one other brand than Eimac is
available (Taylor?). I've heard that Eimac has contracted
out the production of 8877 to China?
73,
Jeff Maass K8ND
Caribbean Contesting Consortium - PJ2T
http://www.pj2t.org
http://home.columbus.rr.com/jmaass/Radio/PJ2T_Aerial.htm
> -----Original Message-----
> From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com]On
> Behalf Of rlm
> Sent: Wednesday, October 22, 2003 10:08 AM
> To: Ed Briggs; AMPS
> Subject: Re: [Amps] Future availability of 3cx1200a7 and 3cx1500a7
>
>
> **** The problem with the 3cx1200A7 (and the 3-1000Z) is that it has
> roughly 7x as much feedback-C (Anode-cathode C) as an 8877. Although
> more feedback-C is beneficial in VHF oscillators, it can be a problem
> in HF amplifier applications. To reduce feedback-C, Eimac came up with
> the 3cx1200Z7. It has about 1/10 as much feedback C as the ...A7. The
> cost is c. $20 more than an ...A7, it uses a 6,3v filament, and it
> requires a better-design socket, so it is not a plug&play substitute..
>
> cheers
>
>
> On Tuesday, October 21, 2003, at 06:09 AM, Ed Briggs wrote:
>
> > I was wondering if it is possible to predict how long the 3cx1200a7
> > will continue to be available from Eimac. I'm considering buying a new
> > amp, and pondering the future availability of the 3cx1200a7,
> > 3cx1500a7, and of course the Svetlana 4cx800.
> >
> > Is the 3cx1200 widely used? I know of two amateur amps in production
> > with this tube, and I wonder if there are non-amateur applications.
> >
> > It seems the 3cx1500a7 is more widely used in non-amateur applications
> > and thus might be a longer survivor. Also, it seems to have a second
> > source.
> >
> > Anyway, if anyone has guidance, particularly wrt. the 3cx1200, I'd be
> > very grateful indeed.
> >
> > Ed
> > N1TS
> > _______________________________________________
> > Amps mailing list
> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
> >
> >
> Rich Measures, AG6K, 805.386.3734. www.somis.org/
>
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