Guy,
> Calling it a dipole with one end woven horizontal is apt. The folds in
> the "weave" are designed to minimize radiation from the weave, and so
> force all the radiation from the other end so far as is possible, and
> cancel fields as much as possible underneath to keep induced current
> in the dirt from the folded end as low as possible.
I don't think you mean the FCP does not radiate - it radiates in such a
way as to balance the fields in the lossy medium (soil). Remember, it
is the *net* field - not the individual fields - that causes current
flow (displacement currents) in the medium.
How well the field cancellation works to reduce losses is a matter for
debate and testing. However, the concept of reducing the interaction
of the fields on the lossy soil is well established - whether it be by
"shielding" the soil from the fields (the traditional "dense" ground
system) or by reducing level of the fields reaching the soil by raising
the radials/counterpoise significantly (from slightly raised radials to
the true "groundplane" antenna more than 1/4 wave high).
One can argue from a philosophical perspective that there is no debate
about the physics. The real question is whether the FCP is, in fact,
operating as the hypothesis states (provides the claimed results) or
is "pseudo science" in the class of fractals, the E-H/CFA antennas
and the folded monopole.
Anecdotal reports indicate good results for the FCP but only well
monitored field intensity testing (field strength measurements)
comparing a FCP and a dense radial (reference) system can definitively
answer the question but such field verification is very difficult due
to the size of the antennas and the requirement that they be done at
1.8 MHz due to frequency related ground behavior.
73,
... Joe, W4TV
On 8/1/2012 6:59 PM, Guy Olinger K2AV wrote:
> The "FCP" only refers to the folded part, it's not a complete antenna.
> The pattern depends on what you do with the wire attached to the FCP.
> If it's an L instead of a straight dipole, you will get more high
> angle radiation.
>
> FCP is terrible on the ground. Though lower heights will work with
> increasing loss, 8 feet and up is recommended. I know a few who
> mounted it on the back yard wooden fence which kept it at six feet up.
> The fence in the rain had a dielectric effect. But it was something
> that he could actually get away with, so he didn't care. The back
> fence was 70 feet long across the back. The guy's lot was 75 x 115.
>
> Calling it a dipole with one end woven horizontal is apt. The folds in
> the "weave" are designed to minimize radiation from the weave, and so
> force all the radiation from the other end so far as is possible, and
> cancel fields as much as possible underneath to keep induced current
> in the dirt from the folded end as low as possible. An inverted L over
> an FCP is a vertical dipole with one end folded, and the other with a
> 90 degree bend in it.
>
> For those of you in some of the prior discussions, tell me if the
> folded end of the dipole is a counterpoise by your definition. If not,
> what do you call it.
>
> What exactly makes it a counterpoise instead of just a folded end to a dipole.
>
> 73, Guy
>
> On Wed, Aug 1, 2012 at 12:37 PM, Jim WA9YSD <wa9ysd@yahoo.com> wrote:
>> With all due respect:
>>
>> The FCP is a dipole. One end is vertical while the other is weaved
>> horizontal on or near the ground.
>>
>> The 1:1 isolation Trasformer / Balun serves its purpose as well as stopping
>> those nasty common mode
>> conditions.
>>
>> The FP and CY9 came on and I was not able to work them single hop conditions
>> just did not favor me. I heard
>> CY9 on and off but QSB just hindered me. If any one worked them with the
>> same distance as I but with the
>> FPC then there is some high angle component.
>>
>> I had thought that low angle radiation is what is desired for 160M. So what
>> does the FPC patterns show
>> on the mapping program?
>>
>> Stay on course, fight a good fight, and keep the faith. Jim K9TF/WA9YSD
>> _______________________________________________
>> UR RST IS ... ... ..9 QSB QSB - hw? BK
> _______________________________________________
> UR RST IS ... ... ..9 QSB QSB - hw? BK
>
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UR RST IS ... ... ..9 QSB QSB - hw? BK
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