[Amps] Any designs for 4CX1000A on 2m ?

[Dr. David Kirkby]

On 06/ 7/11 03:10 AM, Fuqua, Bill L wrote:
> About 10 or 12 years ago there was one in QEX.
> You may have to check the QEX data base.
> 73
> Bill wa4lav

Thanks Bill.

Mark, K5AM sent me this link. Is that the amp you mean?

http://www.zianet.com/k5am/2mkw.pdf

or was there another?

Dave G8WRB.


>
> ________________________________________
> From: amps-bounces at contesting.com [amps-bounces at contesting.com] On Behalf Of Carl [km1h at jeremy.mv.com]
> Sent: Monday, June 06, 2011 6:57 PM
> To: Dr. David Kirkby; 'AMPS'
> Subject: Re: [Amps] Any designs for 4CX1000A on 2m ?
>
> K2RTH (SK) had a pair on 2M for decades, Im not sure which configuration but
> Id suspect parallel with a flat plate line.
>
> Ive heard from several that it ran well over 2K out.
>
> Carl
> KM1H
>
>
> ----- Original Message -----
> From: "Dr. David Kirkby"<david.kirkby at onetel.net>
> To: "'AMPS'"<amps at contesting.com>
> Sent: Monday, June 06, 2011 4:24 PM
> Subject: [Amps] Any designs for 4CX1000A on 2m ?
>
>
>> Are there any published designed for 2m linears using the 4CX1000A tube? I
>> tried
>> to build an amp with a pair of them in push-pull grounded screen, but it
>> never
>> worked well. Now thinking about something more modest - a single tube,
>> using a
>> conventional socket with cathode grounded.
>>
>> I know there was a design in the ARRL handbook for a single-tube grounded
>> screen
>> amp, which gave me the idea of a push-pull amp, but I never got it working
>> very
>> well (it was drawing positive grid current with an output of only 300 W.
>> Had I
>> pushed the input power, it would have probably damaged the tubes).
>>
>> I've seen comments that the grounded screen amp in the ARRL handbook was
>> not
>> such a good idea, which is making me think it might be better to go along
>> the
>> route suggested in the data sheet. i.e.
>>
>> cathode at DC ground
>> grid at -60 V
>> screen at +325 V
>>
>> I've also seen a design on the web which ties the screen and grid
>> together, to
>> use the tube as a triode, but again I want to avoid that.
>>
>> Are there any decent designs for a 2m amp with a conventional usage of
>> voltages?
>>
>> I recall John Nelson, GW4FRX telling me the 4CX1000A presents more
>> problems to
>> hams than any other tube, so I don't think it's the best device ever made,
>> but I
>> happen to have quite a few sitting around collecting dust.
>>
>> Does anyone have a socket for one? I built the grounded screen sockets
>> myself
>> (had access to a workshop at the time). But I want to buy an Eimac socket,
>> with
>> the screen decoupling capacitor for this.
>>
>> --
>> A: Because it messes up the order in which people normally read text.
>> Q: Why is top-posting such a bad thing?
>> A: Top-posting.
>> Q: What is the most annoying thing in e-mail?
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>
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-- 
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?