[Amps] Screen Power Supply.

[Bob Maser]

I've always felt that copying a proven design is more expedient that 
reinventing the proverbial wheel so when I came across George Daughters K6GT 
design for the 4CX1600 amp in the 2000 ARRL handbook, I decided to copy some 
of the circuits he outlined.  The power supply looked good to me so I 
started looking up the component parts in my trusty Mouser catalog.  When I 
got to the screen supply section, I came across a NPN transistor designated 
as Q1 MPSU010.  I cannot find this part listed anywhere.  I believe that it 
is manufactured by Central Semiconductor Corp  because I see other MPSxxx 
parts made by them but I can't find it on their website.  Can someone lead 
me to a source for this part and a description?  I am going to take a 300VAC 
Peter Dahl transformer that I found a Dayton a few years back and full wave 
bridge it up to 420VDC and then I want to "regulate" it down to about 350VDC 
with some series Zeners.  I am not using the 4CX1600 but that tube seems to 
have a lot in common with the 4CX1500B, the tube I'm going to use.

Any help on this?

Thanks,
Bob Maser  W6TR