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Re: tubes??? 4CX250F
Subject: Re: tubes??? 4CX250F
Date: Fri, 23 May 1997 21:00:17 +1000
From: Phil Chalk <philoc-at-ozemail-dot-com.au>
Organization: Secure_Logic
To: Tesla List <tesla-at-pupman-dot-com>
References: 1
Tesla List wrote:
>
> Subject: tubes??? 4CX250F
> Date: Thu, 22 May 97 05:54:18 UT
> From: "William Noble" <William_B_Noble-at-msn-dot-com>
> To: "Tesla List" <tesla-at-poodle.pupman-dot-com>
>
> a long time ago I used to work for Collins radio -
Lucky boy !
4CX250F. If I remember right, these came out of kilowatt HF airborne
> commercial radios.
I was once the proud owner of a KWM-1 (I hope to get it back again some
day)
The KWM-1 (ex Mawson Base, Antarctica) was originally fitted, I believe,
with a pair of 4X150A's (glass base), but when I got it it had a pair of
4CX250B's in it (I still have a brand new pair, by Eimac) These are a
ceramic (Berillium Oxide !) based, higher power version. The 'C' in 4CX
says 'Ceramic'. They are a beam power tetrode, from memory.
I don't recall the specs, but in the KWM-1 they ran with 2kV dc on the
plates, and were good for about 1500-2000W PEP, I think.
I think I have some data on them, somewhere - at least an Eimac
spec-sheet. If I can find any I'll mail to you. The 4CX250B data
should be very close in most respects - I do not know the significance
of the 'F' suffix.
I also have no experience (yet, unfortunately) of tube Tesla coils, but
I think they could be of some use. Certainly that thought crossed my
mind, for my pair. However they do need a LOT of forced-air cooling
(with special sockets, chimneys, etc) for full-rating operation, and
Plate dissipation is very much reduced without it. Others here will
have a better idea of their suitability.
Cheers,
Phil Chalk.