>
>I have a 4CX15000 that I would like to trade for a 4CX5000. Email me if
>interested.
>
>Rick
>
/\ The 4CX15,000A/8281 is quiet similar to the 4CX5000A/8170. Both use
the same socket, have handy handles, and have 7.5V filaments. For the
8281, the anode current, Filament current, and voltage ratings are
roughly a third higher than for the 8170. This allows the user to
produce up to about 1/2 of 1 S-unit (3db) more watts. However, the 8281
can be operated from a 8170's power supply with ease. The major
difference between these tubes is that different diameter chimneys are
used. Also, when switching tubes the neutralization and the brid bias V
need to be touched up. The big advantage of the 8281, is a freer-flowing
anode cooler. Thus, when an 8281is used at 8170 ratings, it can be
cooled by a quiet slow-speed/1750 RPM blower. However. the 8170 needs a,
Much more noisy, high-speed/3450 RPM blower to ram air through it's
narrow cooler.
- Both tubes can be rebuilt/recarburized and both make for an unboring
project. However, it is my opinion that it not a good idea to use more
power than is needed to communicate. Also, using such a beast to "win" a
radio contest does not warrant a feather in one's war bonnet. / see my
Website for info on designing tetrodes-with-handles/20db+ gain linear
amplifiers.
have fun, Rick.
- R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures.
end
--
FAQ on WWW: http://www.contesting.com/FAQ/amps
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
|