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Re: tubes??? 4CX250F

Subject:     Re: tubes??? 4CX250F
      Date:  Thu, 22 May 1997 17:41:19 -0500
      From:  Chuck Curran <ccurran-at-execpc-dot-com>
        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  - my office was near a
> field
> service center where they repaired airborne radios.  I "trained" the
> technicians to save interesting things for me.  I just looked in a
> drawer of
> "interesting things" and I have two octal based tubes, JAN8621, also
> numbered
> 4CX250F.  If I remember right, these came out of kilowatt HF airborne
> commercial radios.  I never have tested them, of course, I just saved
> them
> because I liked the fins (and one is gold plated) and thought they would
> be
> nice for a "tube collection".  Are these of potential interest for a
> small
> tesla coil??  not too suprisingly, this tube isn't in any of the 3 radio
> amateur handbooks I have (1953, 1962, 1976) nor is it in my RCA
> receiving tube
> manual.  The tube sitting here as I write was made by Eimac and if I can
> guess
> the date code, in the 21st week of 1974.
> 
> I also have an RCA tube of similar style, the base is 4 concentric rings
> (hence a triode??), labled 463 (this is the gold plated tube) - filament
> continuity is OK
> 
> comments??

William:
        The 4CX250 series of tubes were commonly used in Amateur Radio
Linear
Amplifiers when I was active.  The 4CX250 was a favorite for use in the
2 meter Ham band.  The 4CX250B has a 6 volt filament while the
4CX250Fuses a 26.5 volt filament.  It's a tetrode with full rated specs
useful to 500 Mhz, a real nice tube even by today's standards.  I've
owned a bunch of those and still have some 3-400Z's, 4-440A's and one
PL-175A in a box in the basement.  Some day I'll put them to good use
again!  I've got the full specs on the 4CX250 if anyone needs them.

Chuck Curran