[Amps] Anyone recognize this amp / circuit?

[Jim Hargrave]

Mark,

Try the 1987 ARRL handbook. The 2x4-400 amp is described on page 30-40.
Title "An economy 2 KW Amplifier"
 
I built mine (2 tubes) from scratch in 1979. I switch sections of 
BC-610 RF coils for the Pi network and it covers 80-10M. 
Its still plugging along.

The 4-400 tubes are rated to 110 Mhz, so it can be configured for 6M.

    73s de Jim
       W5IFP
 



 

  > -----Original Message-----
  > From: Amps [mailto:amps-bounces at contesting.com]On Behalf Of Mark
  > Beckwith
  > Sent: Wednesday, March 20, 2013 11:34 AM
  > To: amps at contesting.com
  > Subject: [Amps] Anyone recognize this amp / circuit?
  > 
  > 
  > I have acquired a homebrew amp as follows:
  > 
  > It has two 4-400s in parallel in grounded grid (with a hole for 
  > a third one, 
  > FWIW).  The bandswitch has positions 80-40-20-15.  It has TWO 
  > 30A Filament 
  > transformers with 110V primaries wired in series with the outputs in 
  > parallel.  Input is not tuned.
  > 
  > HV power supply is separate, outboard.
  > 
  > This seems like something I might have seen in an old handbook? 
  >  Does it 
  > ring a bell for anyone in this group?
  > 
  > Fun project.  Any conjecture about how I would fare adding 160, 
  > 15 and 10 
  > meters?
  > 
  > Thanks in advance for any posts in response.
  > 
  > 73 - Mark, N5OT 
  > 
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