Shield the E-probe?
#1
Gentlemen & members!


Judging from my question, it will be evident I have a very dim view of antenna theory, so pls be gentle...


I live on the top floor of a high rise with a great view of my city.
I plan to place both the ferrite antennas & E-probe on the balconny.

However, living as I do, I assume there is plenty of sources of interference coming from lower floors.


Question: is it possible to build a shielding around the probe in the (potentially) offending sectors?



Regards/M
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#2
(2017-04-22, 14:54)Max_Headroom Wrote: Gentlemen & members!


Judging from my question, it will be evident I have a very dim view of antenna theory, so pls be gentle...


I live on the top floor of a high rise with a great view of my city.
I plan to place both the ferrite antennas & E-probe on the balconny.

However, living as I do, I assume there is plenty of sources of interference coming from lower floors.


Question: is it possible to build a shielding around the probe in the (potentially) offending sectors?



Regards/M

The Electromagnetic impulses consist of two fields... magnetic and electric. The ferrites receive magnetic energy, the E probe receives electrical. The H field antennas are also susceptible to some types of electrical signals. If we don't want Electiric energy in the ferrites, we can shield them... electrically conductive material can be wrapped around the loops, except for a gap the length of the shield... (if the shield were continuous, it would be 'shorted out'... and nothing would get to the antenna.).. the shield is then connected to ground, and a large percentage of any 'electrical' interference would be eliminated. The desired magnetic portion would then be allowed to reach the antenna.
On the other hand...
The E probe is designed to detect the electrical energy of the impulses. If you shield it, you short that to ground.  Therefore the E probe is not to be shielded. By it's nature, it is relatively immune to the magnetic portion. If you read the documentation, the E probe needs to be outside, away from any structures or noise sources, at least 2-3 meters or higher above ground.  The air space between the probe and earth is an integral part of the probe.

Because of what I've determined about my environment and through experimentation,
I use these types of electrical shielding for my ferrite antennas
[Image: DSC03574A-S.jpg]
Signal images of the improvement this shield design produced
when used with RED system dual ferrites
http://www.ourspecialnet.com/Weather/Pesky-Project/
The complete enclosure on the right is BLUE delta config ferrites,
produces less dramatic shielding characteristics rhan those of the two Red system
antennas, on the left. The 'box' version is not quite as effective.

and my E probes are mounted as
[Image: E%20Probes-S.jpg]

As you can see, none of the noise reduction
experiments are pointed at E probe....
properly located, installed and
configured in the controller
the E field will be well behaved.
You may have a very tough
environment, in a high rise with
a balcony.
                   TwinHollies WeatherCenter  Frankfort KY, USA
  Americas Operators at Sferics.us
        Stations: 689, 1439
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#3
Cutty, many tnx for your post.

A lot is clearer now.
My current plans is to shield the ferries in opened-up copper pipes.
Reading about this shielding, states that you need to have a distance between the copper & ferrites, to avoid "magnetic vortice effect"?

Any thoughts of optimum distance, or just simply "more is better"?


/M
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#4
More is better, but 50mm is enough

For radio listening where a high Q is desirable, I would choose 80-100mm

/Richo
Stations: 584, 585, 1570
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#5
:-) Many tnx/M
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