[AMPS] K2RIW Amps

measures 2@vc.net
Sun, 25 Feb 2001 08:03:55 -0800


>
>Arne Gjerning wrote:
>>
>>When I helped operate EME station at the 150 ft Stanford Univ dish in
>>the late 70's, the amp on 432 MHz was a RIW (2ea 4CX250B) and it read
>>900W out to a Bird wattmeter. I would not have believed it if I had not
>>seen it, but that is one super amp for 432.
>
>In class B or C with a lot of drive, you can indeed get that kind of
>power from a pair of 4CX250Bs - but that's CW, not linear.
>
>The practical limit for good linearity is about 500W in strict class AB1
>(ie zero g1 current).
>
>The Eimac data sheet for 4CX250Rs suggests more power is available...
>but look how the linearity suffers!
>
I ran a pair of paralled 4cx250Rs on 2m SSB.  The tank was 1/4 wave.  
With a screen current of c. 5mA (@400screen-v), the linearity was good. 
Output was c.900w PEP on SSB. 10w drove it.  

cheers

-  Rich..., 805.386.3734, www.vcnet.com/measures.  
end


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