Hi Tony,
In addition to my previous introduction I forgot to say a moint :
(3)There is a length dependency.
The two electrodes earth anntena of 2 times long can be received 3 dB
up.
Confirm the above.
73
7L1RLL Rick
On Tue, 2010-08-17 at 10:10 +0900, Rick Wakatori wrote:
> Hi Tony,
> Thanks for the confirmation on directivity of the two electrodes earth
> antenna.
> The JA5FP's group said as follows:
> (1)Same directivity exists in a short distance.
> (2)Dried earth is good for transmittion. Wet ground does not work as a
> good antenna. an imaginal loop may be shortened in a half.
>
> Try the above phenomenons.
> 7L1RLL Rick
>
> On Mon, 2010-08-16 at 15:35 +0100, Tony wrote:
> > Yesterday I spent some time playing with different antennae.
> > I started by laying out another wire 52m long orientated roughly
> > north/south and then I shortened my original wire also to be 52m and
> > this one is east/west, both terminated with an earth rod.
> > Results were not as expected however as although the two earth electrode
> > antennae show most definite directivity they were the wrong direction.
> >
> > I monitored BBC R. Bristol on 1548 KHz which is about 500 Km due east of
> > me and on the inverted L (tuned VSWR 1.6:1) I could just detect a
> > carrier heterodyne, on the N/S earth electrode antenna it was S1 but on
> > the E/W earth electrode antenna it was S3.
> > RNE5 on 531 KHz about 960 Km due south of me was S3 on the E/W and S8 on
> > the N/S
> >
> > HGA22 (135 KHz) to my east was S4 on the E/W and S1 on N/S
> >
> > Readings were taken about 12:00 utc so most definitely ground wave.
> >
> > I was expecting the directivity to be broadside on the earth electrode
> > antennae, but they seem to behave like a Beverage in that respect, but
> > something that I think I will investigate further, maybe see if there is
> > any difference if I terminate them with a resistor.
> > I'm sure Mal is correct though that they would be useless to TX through
> > but for RX they seem to have possibilities especially after dark as they
> > are a lot quieter.
> >
> > All good fun.
> > 73, Tony, EI8JK.
> >
>
>
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