There is also a nice design (from waht I can tell), in the
3rd Edition (1972) of the 'Radio Amateurs VHF Manual' on
page 106 for a Kilowatt Amp for 50 and 144 MHz, that uses
three 4CX250R (Ruggedized) (sim to 4CX250B) that might be
of interest to you. Text says that plate can be anywhere
from 800 to 2000 vdc without having to alter screen or
drive levels to any great extent.
I didn't find a 'builder' callsign as is on some articles,
so all I can suggest is try to find a copy of this edition
or contact ARRL (if you're a member) and get an archive
copy from them.
Note: A listed variation for the design uses 4CX350A's.
I wish I knew more about this type of tube. I have several
4X150A's and D's that I'd like to make use of, but I'll need
to find an Elmer that has experience with these, before I
start a project like THAT :-/
73 - Bruce
On Tue, 24 Apr 2001, Bob & Linda McGraw K4TAX wrote:
> There is a fine article in THE VHF/UHF DX BOOK publlished by RGSB which
> details a pair of 4CX250B's used in parallel for 432 MHz. This
> amplifier is known as the K2RIW power amp. The 4CX300A's in parallel
> will serve the same form, fit and function with the noted socket
> changes.
>
> George L Clute wrote:
> >
> > I should have qualified my question...i.e. running a typical operation of
> > 2000 to 2500 DC plate voltage under 250 Mhz in Class AB1 configuration. Has
> > anyone constructed three 4CX350A's or 4CX300A's in parallel operation with
> > one KW DC input. I suspect from the answers here that it has not been
> > accomplished and may be impossible to resonate the plate circuit on
> > frequencies above 30 Mhz due to the plate capacitance of three tubes in
> > parallel.
--
FAQ on WWW: http://www.contesting.com/FAQ/amps
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
|