Hi Roger
It has been very interesting to follow this experiment :) Keep up the
good work!
Best regards from Norway.
LA5VNA Steinar
loc:JO59jq
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José Ros software not supported
Den 10.01.2013 00:04, skrev G3XBM:
>
> As a final (?) remark, my signal is STILL being copied far and wide this
> evening (701km) despite NOTHING at all in the air, just a bit of wire across
> the lawn to an earth rod and another to a pipe in the shack.
>
> At this point I AM stopping!
>
> 73s
> Roger G3XBM
>
> --- In [email protected], Rik Strobbe wrote:
>>
>> Roger,
>>
>>
>>
>> based on A1 = ((1+sqrt(P2/P1))/((P2/P1)-1))*A2.
>>
>> where A2 (area above ground) = 15m^2
>>
>> For 3dB difference P2/P1 = 2: A1 = ((1+sqrt(2))/(2-1))*15 = 36m^2.
>>
>> For 1dB difference P2/P1 = 1.26: A1 = ((1+sqrt(1.16))/(1.16-1))*15 = 195m^2.
>>
>> Taking into account all uncertainties the last value (195m^2) is quite close
>> to the 290m^2 calculated earlier (abt 50% or 1.8dB error).
>>
>> Some more "datapoints" might clear things up, but I understand that you are
>> going to stop the experiment for now.
>>
>> Thanks for providing all the experimental data.
>>
>>
>>
>> 73, Rik ON7YD - OR7T
>>
>>
>>
>> ________________________________
>> Van: [email protected] [[email protected]]
>> namens G3XBM [rogerlapthorn@...]
>> Verzonden: woensdag 9 januari 2013 20:51
>> To: [email protected]
>> Onderwerp: [rsgb_lf_group] Working out the "loop in the ground" area with
>> earth electrodes
>>
>>
>>
>> Rik,
>>
>> Maths is not my strong subject but I have tried to plug in values in you
>> equation and am getting odd results, but I may have made mistakes.
>>
>> The difference on a local (G4HJW) 9km away between an earth electrode
>> antenna with around 15 sq m in the air (the original configuration) and with
>> zero loop in the air (today's configuration with the wire on the grass) is
>> around 3dB averaged over a number of spots. When I plug these numbers in
>> (should I use 2x for power or 3 (dB) ?)
>>
>> With G3ZJO who is 79km there is very little difference, perhaps 1dB between
>> the loop on the ground and with 15m sq of the structure in the air.
>>
>> If you have a minute, would you plug the figures in and see what you get
>> please?
>>
>> [Loop part that is in the air was 1.5m (high) x 10m long with the rest on
>> the ground. This was for the original configuration.
>>
>> With the "wire on the grass" version today, there is zero wire in the air,
>> so air loop area is zero.]
>>
>> 73s
>> Roger G3XBM
>>
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