Date: Sat, 10 Jun 2017 14:09:05 -0700
From: Paul Baldock <paul@paulbaldock.com>
To: "Amps group" <amps@contesting.com>
Subject: [Amps] Ferrite Core for 160M PI Output ?
Message-ID: <593c5ff4.4bd1620a.e42b5.0bd9@mx.google.com>
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<When I said Ferrite I should really have said Toroidal so as to
include Iron Powder.
- Paul
What's the best PI Output Ferrite Core(s) to use for a 1.5KW tube amp?
Thanks
- Paul
KW7Y
## Powdered Iron. #2 MIX. These are the RED ones.
T225-2B. Beware, the T225-2A is only .5 inch thick ...
IE laying on the table with hole pointed at the ceiling, its
.5 inch tall.
## The T225-2B is a full 1 inch thick. You require at least 2 of
them
for 1.5 kw out for cw and ssb. For RTTY, you require 3 of them.
## these have been in use since the 70s..for 160 + 80m.
## I think marv calculated the heat at aprx 57 watts of diss, regardless
of how many core are used. They run hot..normal.
## If 3 used, the entire mess ends up being 2.25 inch OD x 3 inches
long.
Bigger OD and length, once the wire is wound onto them.
I found some air dux..which used 12 or 14 gauge wire.... and had the
turns
spaced closer than normal air dux. Worked perfect for the 160M
conversion
project I was working on. Zero heat vs the stack of torroids. The air
dux
weighed nothing vs the hefty weight of the 3 stack I also tried. The
airdux
ended up being aprx the same diam and length as the torroid stack.
## space wide, the torroid stack save me nothing. 160m is pretty
forgiving,
with long leads, coil close to cabinet side walls etc.
Jim VE7RF