TopBand: Elevated Radials Test #1

[km1h @ juno.com]

On Fri, 10 Apr 1998 09:50:39 EDT CQ K8DO <CQK8DO@aol.com> writes:
>Carl.....How far away from the antenna and in what direction in 
>comparison to
>the receive antenna is the second set of elevated radials?  How long 
>is the
>wire connecting the two sets of "radials"?

The 2nd radial field is behind the test antenna as far as the RX site is
concerned.
The connecting wires are 130' long which is the base seperation between
the antennas.


>The thought here  is that the floating set of radials is forming a 
>horizontal
>array with the transmit radials to enhance the groundwave in the 
>direction of
>the receive site....

If there was parasitic coupling or horizontally polarized reradiation
from any of those wires why would I see a change at a site that is 200'
lower in elevation and using a vertically polarized antenna?


Next, the 150' on the ground is way too long.... Due to ground 
>proximity the
>resonant length of the radials will be roughly (very) 80% of length 
>when
>elevated and driven as  dipole pairs.... These long radials will 
>introduce
>considerable reactance back to the feed point


I just dont buy into the reasonant argument Denny. Since all of my
radials ...including the original set of six at 130'...are strung over
tree branches I seriously doubt if reasonance has any bearing on
performance. The trees, pine sap, etc have already done their best to
detune them.

I also noted the amplifier control settings between the original 6 and
the two fields...there was only a very minor change required. What I
suspect is that the feed impedence has changed only a few ohms at best
but the radiation at the lower angles has improved a bit.

Now....all I need is some good propagation.

73  Carl   KM1H 

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