- Original Message -
From: "Tom W8JI"
To: "topband"
Sent: Tuesday, August 20, 2013 4:00 PM
Subject: Re: Topband: RX antenna transformer winding (pure
resistancetransformation issues)
Unless you have a system with pretty high common mode impedances, winding
spacing means nothing.
On 8/20/2013 1:00 PM, Tom W8JI wrote:
By squeezing or spreading turns to change mutual coupling between
turns, a T157-2 core can have almost 2:1 impedance shift! That tells
us it has considerable flux leakage.
So-called "self-shielding" and it's inverse, leakage flux, also depend
on permeab
Unless you have a system with pretty high common mode impedances, winding
spacing means nothing.
** Contrary to what you have stated elsewhere
Where? Please quote it in enough context to see the meaning. I'll certainly
clairfy it or correct it if possible, because I don't want to mislead
anyo
I'm putting out 60 1/4 wave radials for my 160m Inverted L on the
ground. 4-5 of those radials will end up in my pond with anywhere from
5-10 feet to 25 feet in the pond for those 4-5 radials. The pond is to
the NN/E of the Inverted L.
Should I:
1) Just attach to each radial a heavy enou
On Tue, Aug 20, 2013 at 3:00 PM, Tom W8JI wrote:
> The ARRL in some publications, for example, teaches us toroids are
> "self-shielding". In fact, many toroidal cores have significant flux
> leakage.
>
That is for sure. I was following a thread in an SWL or AM BCB group a few
months ago, where
I had additional offline conversations with Rick (N6RK), and Carl (KM1H),
and below is my official response to my original post about RX antenna
transformer windings and complex impedance measured on the primary side of
the transformer depending on how they are wound.
There are several things th
On 8/20/2013 11:31 AM, Don Kirk wrote:
But I saw the complex impedance phenomena even with smaller diameter cores
(using different grade of material), and here is my actual FT 50-43 data as
an example.
One missing piece in understanding what you're seeing is the fact that
mu (permeability) is
If I can add my $0.02 worth here...
I have never found a better ferrite core for RX antenna transformers than
the Amidon BN-73-202 (Fair-Rite 2873000202). I also used to use
side-by-side stacked ferrite beads (eight FB-73-202 in two tight stacks of
4) to make "binocular cores", but that never work
I had additional offline conversations with Rick (N6RK), and Carl (KM1H),
and below is my official response to my original post about RX antenna
transformer windings and complex impedance measured on the primary side of
the transformer depending on how they are wound.
Rick N6RK said
> The way out
