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EH Antenna Revisited
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January 14th 04, 07:26 PM
Richard Clark
Posts: n/a
On Wed, 14 Jan 2004 11:17:24 -0600 (CST),
(Richard Harrison) wrote:
OK. I read the first page: "Welcome to the Wonderful World of EH
Antennas". It said nothing of why I should be interested. Why convert an
existing broadcast antenna to EH?
FCC has a publication, "Rules of Good Engineering Practice for Standard
Broadcast Stations" which includes Mv/m at 1 mile on a radial over
perfect earth from a vertical antenna of various heights. It shows about
195 mV/m for a 1/4-wave grounded vertical.
Let's look at the Data 1 mile out, and compare to the standard antenna
at the same distance:
-3.5dB
-1.24dB
-2.84dB
-1.5dB
+0.66dB (in the direction of the nearby resonating tower)
-0.85dB
How about at the limit of the test @30KM:
-26.9dB
-27dB
-22.7dB
-34.8dB
-29dB @ 16KM (off the chart @30KM)
-32.4dB
This sucker's signal dives right into the ground like a plow.
Obviously the eh antenna suffers a misspelling, it should be POS.
[Art, are you taking notice of the performance of small vertical
dipoles for 160M?]
snip
Why would the EH antenna have interest?
Hi Richard,
Why indeed. This design is a tower mounted, air cooled resistor that
has the advantages of top loading guy wires and nearby resonating
structures (if such could be called advantageous).
If you want to crow about your eh/POS DX contacts 1 mile out, they
better be in the direction of that nearby standard quarterwave
antenna. More's the pity that those living beyond 10 miles may never
hear your fabulous DX report.
73's
Richard Clark, KB7QHC
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