This is primarily directed to Ian but I would appreciate comments from
anyone with experience.
I wish to build a 50MHz amp with either a 4CX250B or 4CX250R, I have both
new in the box. The questions are what are the ideal plate and screen
voltages and idling current in order to obtain the best IMD at 150-180W
PEP output? I have 15W of drive available but efficiency is not
important, I could run close to Class A if it would result in an
extremely clean signal.
I am striving for 3rd order IMD of -35dB or better if that is possible
with these tubes.
Now comes the real question. Am I wasting my time with a tetrode? Would I
be better off just converting an SB-230 with the 8873 and wind up with
-40dB or better IMD at those drive/output levels? Eimac specs indicate
that I can but is this realistic?
I have several 8873/8874/8875's here and can also homebrew around any one
of them.
Again the #1 goal is the best IMD that I can obtain.
Tnx Carl KM1H
_____________________________________________________________________
You don't need to buy Internet access to use free Internet e-mail.
Get completely free e-mail from Juno at http://www.juno.com
Or call Juno at (800) 654-JUNO [654-5866]
--
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
|