Topband: FCP

Guy Olinger K2AV k2av.guy at
Mon Sep 5 00:30:03 EDT 2016

Using #10 bare wire is fine. If that's what you have on hand to use (free
of incremental cost), then by all means use it. It certainly will NOT hurt
anything. There are physical reasons for "bare" and minimizing wire loss
reasons for #12. Bare #10 violates neither of those.

The FCP is a folding trick to severely reduce net RF fields down at the
dirt and reduce losses. We're not trying to make some kind of a feedline
with it where to get a certain Z a wire size changes forces changes in
spacing. The actual single-ended feed Z of an FCP varies quite a bit from
installation to installation. That is expected and normal.

Never adjust FCP dimensions to affect changes in overall feedpoint Z or
SWR. We tried that a long time ago (historical category: Jack's and Guy's
dumb mistakes). Abject failure. Screws up the reduction of net RF fields
down at the dirt and quickly raises loss, fouling the reason for the FCP in
the first place.

The orientation of the FCP with respect to the horizontal part of the L is
pretty much immaterial with respect to pattern or efficiency. Changing the
co-orientation angle will move the feed Z around some. But since an
efficient L over FCP will expose all the natural variability of an inverted
L's feed Z, you will have to deal with that natural variability, which is
far more than the variability caused by the angle between the FCP and the

Hope that has helped.

Also, since W0UCE joined ranks of silent keys in February, we are working
to get up a new web page with a lot more information to take the place of
information formerly hosted on Jack's web page. We ARE working on it and
will have it open to the public as soon as we can. Learning HTML and web
pages (which I had managed to avoid for years) has proven to be quite the
task for this old retiree steeped in IBM mainframes. But I AM getting

73, Guy K2AV.

On Sun, Sep 4, 2016 at 2:02 PM, Art Heft <artandkaren at> wrote:

> Greetings to all from a first time poster...
> I am going to use an FCP with an inverted L for 160.  I have 2 questions:
> 1)  can I run the FCP parallel to the horizontal wire or should it be
> perpendicular?
> 2)  can I use #10 bare wire for the FCP?
> Thanks and 73,
> Art K8CIT
> _________________
> Topband Reflector Archives -

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