Re: Longitudinal Wave Experiment

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "J. B. Weazle McCreath by way of Terry Fritz <twftesla-at-qwest-dot-net>" <weazle-at-hurontel.on.ca>


At 08:47 PM 08/03/02 -0700, you wrote:
>
>Original poster: "David Thomson by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <dave-at-volantis-dot-org>
>
>Hi Ed,
>

<big snip>

>This isn't the same thing.  Lying an antenna on the ground is different from
>burying an antenna or sinking a ground rod.  When I say "lying an antenna on
>the ground," I mean literally lying the wire right on the surface of the
>earth.  No ground rods, no aerials, nothing is buried.  The wire is flat on
>the ground.
>
>I've put this experiment to a friend of mine.  We're going to get two 20
>foot lengths of 4.5" OD plastic pipe and tape two 40 foot long wires to the
>pipe 4.25" apart.  In the middle of these wires we will use the half wave of
>a nearby 1390KHz radio transmitter that happens to be in the line of site
>from my yard.  The long pipes will lie directly on the ground and we will be
>able to turn them to test for angular alignment with the radio station.
>
>A crystal radio will be placed across the two wires in one test to see if
>there is demodulation.  Then the pipes will be lifted as high as possible to
>see if there is a change in performance.  I'll also measure voltage at the
>ground level and at a higher level.  We will also conduct these measurements
>with the pipes rotated in different angles wrt to the transmitter.
>

Dave, Coilers,

What you'll be creating with your two wires taped to the plastic pipe will
be nothing more than a balanced transmission line with a ballpark Z in the
range of 600 ohms (discounting the effect of the pipe).  It may work as an
antenna in the "common mode" sense.  Get a copy of the ARRL Antenna Book,
and/or Low Band DXing by John Devoldere and read up on multi-wire Beverage
antennas.  Many have been used successfully simply laying directly on the
ground, or even on ice as one done on a polar expedition some years ago.


73, Weazle, VE3EAR/VE3WZL
G-1#1214

Listening: 147.030+ and 442.075+
E-mail:    weazle-at-hurontel.on.ca
           or ve3ear-at-rac.ca
Web site:  http://www.hurontel.on.ca/~weazle