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@onetel.net>
To: "'AMPS'" <amps@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.
>
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