From:
Fred Hopengarten K1VR 781/259-0088
Six Willarch Road
Lincoln, MA 01773-5105
permanent e-mail address: fhopengarten@mba1972.hbs.edu
On Mon, 9 Nov 1998 02:03:00 -0200 "PT2HO - Carlos" <pt2ho@contesting.com>
writes:
>The Antenna Book has a receiving loop article for 1.8mhz. I don't
>think it
>is well detailed! I would like to receive some commets about this kind
>of
>receiving loop, also how to buid mine...formulas, schemes, books
>etc...
K1VR: I used ordinary white PVC (plastic) plumbing pipe and made a
cross. The vertical piece is much longer than the horizontal piece so
that it may extend downward into the light duty TV antenna rotator. In
the middle is a "four way" splice (it receives four pieces of pipe). So
three pieces are identical in length and one is longer. The three pieces
of pipe which are the same size each get end caps. Glue everything. Drill
holes in end caps to hold 75 ohm cable TV hardline to the frame with tie
wraps. Paint the whole thing (before applying the coax) with one $1.99
can of black spray paint so that no one will see it.
At the top, where the outer shield of the coax is broken but the
center conductor continues, apply black electricians tape liberally and
then reinforce for mechanical reasons with a small piece of plastic pipe,
held in place with two stainless steel hose clamps. At the bottom, build
circuit into a small box and add connectors ( I used F connectors) and
attach a feedline (I used 75 ohm RG-6).
The hardline will easily hold the shape of a circle, will be held
in place by tie wraps, and, at 20 feet, it is just a scrap from any cable
TV installer.
Rotate to null out signals off an edge, as there is no "gain".
All things considered, a relatively inexpensive project.
Fred K1VR
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