In regards to Carl's last paragraph, the 3cx800a7's in my amp I have yet to
check the date code on and work just fine. They are at lest 4 (or more )
years old, I do treat them according to spec regarding gird current and
warm-up time. As for spec they still offer several db of gain when going
barefoot just won't cut it.
73's,
Gary...wa6fgi
----- Original Message -----
From: "jeremy-ca" <km1h@jeremy.mv.com>
To: "Paul Christensen" <w9ac@arrl.net>; "Amps Amps" <amps@contesting.com>
Sent: Thursday, June 05, 2008 10:27 AM
Subject: Re: [Amps] ALPHA DOA...
> If all these fancy, overpriced, uP based amps would fade away it would
> certainly level the playing field for contesting. I got out of it when it
> became a bigger money pit than owning a boat.
>
> It reminds me of the days that drag racing was fun before the big money
> ruined it. These days I play around in the Nostalgia Class with 1950's
> techonlogy and would like to see something similar return to contesting.
>
> Maybe a boatanchor class and another for SS xcvrs prior to the dual
> receive
> versions.
>
> The 3CX1000A7 certainly is rather robust. I use them in HB 144 and 222 MHz
> amps and have full output spares. My interest in that tube goes back to
> the
> late 60's when I was on the design team for a Jeep mounted KW transceiver
> for the Army at National which started off with the 3CV and was changed to
> the 3CX for reliability.
>
> As long as the 3CX800 family remains available from ISM products it will
> be
> the tube of choice for many existing amps as well as retrofitting all
> those
> 8874 Alphas which have become very cheap on the market.
>
> Carl
> KM1H
>
>
>
> ----- Original Message -----
> From: "Paul Christensen" <w9ac@arrl.net>
> To: "Amps Amps" <amps@contesting.com>
> Sent: Thursday, June 05, 2008 11:30 AM
> Subject: Re: [Amps] ALPHA DOA...
>
>
>>> as long as they work....but if something happens you are trapped,- just
>>> as
>>> you tell.
>>
>> I never thought I would live to see the day when the life expectancy of
>> my
>> old Alpha 70V with its extremely scarce 3CV1500A7 tube may actually
>> exceed
>> that of the microprocessor-based 4CX800 amplifiers.
>>
>> The 3CV1500A7 uses a directly-heated cathode, and is extremely robust. I
>> am
>> on the original tube from 1970 and emission is still excellent.
>> Notwithstanding the boiler, the tube is electrically and physically
>> identical to the 3CX1000A7. Thankfully, I have two new spares that I've
>> been rotating into service for short periods of time as a de-gassing
>> maintenance measure.
>>
>> Every other mission-critical component in the 70V can still be purchased
>> new
>> today, including the OEM vapor components.
>>
>> Paul, W9AC
>>
>> _______________________________________________
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>> http://lists.contesting.com/mailman/listinfo/amps
>>
>
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