[AMPS] Re: 3x4CX250B's

[Jan-Erik Holm]

>
>Just for the record, my 2x4CX250 amp will run 1400 watts out on >144 mhz, as
>measured on a Bird 43, and crossed checked with two different >slugs. I
>could and did run a pair of these tubes on EME for about two >years during
>my active periods. This included skeds, randoms, and contests. >The tubes
>ran cool, as measured with thermocouple in exhaust port.
>
>I used A BUNCH of air, ran them in class B, (P-P design) with >2700 volts at
>about 800 ma, total anode current. I could switch them to a more
>conservative AB1 mode, but since I seldom ran tropo, there was no >need to
>run anything but CW. (Real hams only transmit one tone at a >time!)
>
>When the power out would drop off about 10%, I'd find another >pair to stick
>in there. Most were used, purchased at hamfests. In the last six >years I
>was active on EME, I went thru two pairs and the third set is >still in the
>amp.
>
>4CX250's are real workhorses and are willing to take a lot of abuse.
>However, as has been said before, don't try to run SSB under >these
>conditions unless you have a much bigger gun than your >neighboring hams do.
>
>73,
>
>Larry - W7IUV
>w7iuv@axtek.com
>www.axtek.com/w7iuv
>
>--
Yes here we have a fellow that got things right.
Well, I ran my 3 tuber in class C (work only CW)
and I have seen 2300 - 2400 on the Bird, sure 
that isnt 2500 but I am sure it will do it too.
I have used the same set of tubes for about 8
years, in fact it is the original set of tubes
since the amp first was put on the air.

de SM2EKM


--
FAQ on WWW:               http://www.contesting.com/ampfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm