G2AVJ* asserted that Maxwell had slightly over cooked things and
there where no E and H fields , only vector potentials , may be the
mini-probe is a near field array , as its certainly not big enough for
any other concept ?
As for big Ae's .that's really only down to location, in open
space , then a 1 mile wire Ae will produce some very low s/n
levels , in a urban setting , nothing but volts of noise , its true a
small probe can be located in a low noise position , but this is the
geometry of the noise distribution , not the Ae itself
73 -G..
* Silent Key now
--------------------------------------------------
From: "Stefan Schäfer" <[email protected]>
Sent: Wednesday, July 03, 2013 10:33 PM
To: <[email protected]>
Subject: Re: LF: VK1OD's analysis of the MiniWhip antenna
Wow, thanks.
This can lead to a lively discussion :-)
I think there are some misunderstandings by VK1OD. He states that Roelof
says that: "noise is mainly magnetic". But Roelof means the local noise
and not the far field noise, e.g. from thunderstorms. That is the
difference! The local noise H fields pass the walls rather than the E
fields, in many constellations like urban areas.
Furthermore there can be a significant advantage in the obtainable SNR
compared to a "big" antenna because that small whip antenna can be lifted
easily by several meters above ground, without having a high wind load. A
big antenna with a feed point at ground level and a few meters near the
house may catch a lot of local noise.
For me, here on the institutes roof, the small whip antenna
(https://dl.dropboxusercontent.com/u/19882028/MF/LFMFprobe.JPG) achieved
MUCH better results than the 70m long wire
(https://dl.dropboxusercontent.com/u/19882028/LF/IUP%20Antenne_resize.jpg)...
73, Stefan/DK7FC
Am 03.07.2013 01:02, schrieb Dimitrios Tsifakis:
Hello group,
here is a web page written by Owen, VK1OD with an analysis of how
PA0RDT's Miniwhip antenna works:
http://vk1od.net/antenna/PA0RDT-MiniWhip/index.htm
You may find this interesting.
73, Dimitris VK1SV
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