The PSU is 2000-2500V at 500mA to 1A for the anode. The screen grid requires
a stiff supply at 350V that can source and sink 20mA per valve. Grids
are -55ish volts for a standing current of 100mA per valve. Several designs
fo supply boards exist, Downeast Microwave Tetrode boards (AKA G3SEK) will
do what you need.
I had a K2RIW chassis that I could never get to work - so beware. It was a
pretty accurate copy of the ARCOS design. K2RIWs can be/are difficult. If
yours has never worked, it may be better to forget it and go for a different
design using a triode, especially when you consider the PSU complexity. You
can buy an AM-8155 for less than it will cost you for the K2RIW PSU that
reportadly gives 400W on 432 MHz.
My chassis is now a 70MHz amplifier where it can rather easily produce the
160W required. It is easy to modify the chassis for bands from 50MHz through
144 MHz.
Mike
--
FAQ on WWW: http://www.contesting.com/ampsfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|