Message-ID: <4C6AA6BB.8020004@o2.ie>
Date: Tue, 17 Aug 2010 16:11:55 +0100
From: Tony <ei8jk@o2.ie>
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Subject: Re: LF: Earth electrode antenna tests
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  Hi Stefan

I tried the antennae this afternoon on 23 KHz and the E/W wire is 12dB=20
up on the N/S wire.
I have no idea what I was receiving as I was using a FRG-7700 which only=
=20
displays to the nearest KHz.
When I disconnected the far end from the earth stake the signal dropped=20
by 18dB, the receiver is at the eastern end of the E/W wire and the=20
northern end of the N/S wire.

I will try sub 10 KHz when I sort out where my local QRM is coming from.

Tony, EI8JK.


On 16/08/2010 22:16, Stefan Sch=E4fer wrote:
> Hello Tony,
>
> Thanks for that interesting work!
> Could you extend the measurements to the VLF band? It would be=20
> interesting what the levels and directivity would be there.
>
> 73 and pse a sked for your upcoming LF stn! :-)
>
> Stefan/DK7FC
>
> Am 16.08.2010 16:35, schrieb Tony:
>>  Yesterday I spent some time playing with different antennae.
>> I started by laying out another wire 52m long orientated roughly=20
>> north/south and then I shortened my original wire also to be 52m and=20
>> this one is east/west, both terminated with an earth rod.
>> Results were not as expected however as although the two earth=20
>> electrode antennae show most definite directivity they were the wrong=
=20
>> direction.
>>
>> I monitored BBC R. Bristol on 1548 KHz which is about 500 Km due east=
=20
>> of me and on the inverted L (tuned VSWR 1.6:1) I could just detect a=20
>> carrier heterodyne, on the N/S earth electrode antenna it was S1 but=20
>> 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=
=20
>> 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=20
>> electrode antennae, but they seem to behave like a Beverage in that=20
>> respect, but something that I think I will investigate further, maybe=
=20
>> 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=20
>> through but for RX they seem to have possibilities especially after=20
>> dark as they are a lot quieter.
>>
>> All good fun.
>> 73, Tony, EI8JK.
>
>
>