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[Amps] Need some amplifier advice

To: "" <>
Subject: [Amps] Need some amplifier advice
From: Rob Atkinson <>
Date: Sun, 30 Jun 2019 07:19:54 -0500
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There's absolutely nothing wrong with a center tapped FW rectifier,
choke input design power supply since the mode is RTTY which is
non-dynamic; therefore, the power supply can employ a 10 Henry choke
and roughly 8 mfd capacitance, which brings the possibility of oil
caps and their long life in as an option, plus one or two bleeders in
parallel.   All nice and simple and probably still running after we
are all SK.  Gas rectifiers are FB; except mercs unless you know how
to handle them.  I recommend Xenon also, along with Carl.   Yes you
have to have a filament supply tranny that is rated for the B+.  So
what.   AM broadcast rigs have run these arrangements for decades no

The one manufactured amp out there that is seen fairly often and comes
closest to your 500 watt loafing and other circuit demands, is the
Heathkit Warrior.   Swap the 811As for four 572Bs.  Of course it is a
kit amp so you have to go through it and they've usually been modified
from stock now.   But they're practically being given away these days,
because they weigh in at around 100 lbs so most hams don't want to
deal with them.  I've heard in the past that they are sought after by
RTTY ops, especially the green keys crowd, for precisely the reasons
you gave.  They're supposed to sit there and put out 500 watts all
day.    What you need to research and look for are amps made in the
early 1960s that were designed for both AM and SSB.  Besides Heathkit,
EFJ and Hallicrafters had some models.  The Thunderbolt Carl mentioned
is even better than the Warrior.  Pair 4-400As grid driven.  These
amps did not cover 160.  One drawback with the Warrior is finding four
Cetron or United 572Bs.  You probably want the higher plate
dissipation for continuous duty.

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