Message-ID: <5071A12B.3040601@iup.uni-heidelberg.de>
Date: Sun, 07 Oct 2012 17:35:07 +0200
From: =?ISO-8859-15?Q?Stefan_Sch=E4fer?= <Stefan.Schaefer@iup.uni-heidelberg.de>
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References: <5070C574.4030005@iup.uni-heidelberg.de> <0C7651504C4A4734972F6FEAAB324A6A@AGB> <54F387408260412DA3B43C6D071054DF@acerf441e6fc4f>
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Subject: Re: LF: GRRRRR!! Now i know...
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Hi Edgar,

The probe is grounded directly on the aluminium tube which holds the 
probe. But in a next step i want to move this grounding point 70cm away 
from the probe, i.e. directly on the pole. Maybe there is a galvanic 
coupling which runs some current in a loop out of coax and mast. This 
loop may now be to close to the circuit and may induce a H field in the 
structure. I use a common mode choke in series to the coax but its 
common mode reduction is not infinity for all frequencies. Maybe there 
are even some resonances... It becomes complex :-)

73, Stefan/DK7FC

Am 07.10.2012 13:13, schrieb Edgar J Twining:
> Hi Stefan,
>                Following Grahams comments.
> 1. What is the ground for you antenna?
> 2. Is the steel ladder/ frame work next to the antenna pole 
> re-radiating any signals?
> Regards Edgar
> Moonah, Tasmania.

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Hi Edgar, <br>
<br>
The probe is grounded directly on the aluminium tube which holds the
probe. But in a next step i want to move this grounding point 70cm away
from the probe, i.e. directly on the pole. Maybe there is a galvanic
coupling which runs some current in a loop out of coax and mast. This
loop may now be to close to the circuit and may induce a H field in the
structure. I use a common mode choke in series to the coax but its
common mode reduction is not infinity for all frequencies. Maybe there
are even some resonances... It becomes complex :-)<br>
<br>
73, Stefan/DK7FC<br>
<br>
Am 07.10.2012 13:13, schrieb Edgar J Twining:
<blockquote cite=3D"mid:54F387408260412DA3B43C6D071054DF@acerf441e6fc4f"
 type=3D"cite">
  <meta content=3D"text/html; charset=3DISO-8859-15"
 http-equiv=3D"Content-Type">
  <meta name=3D"GENERATOR" content=3D"MSHTML 8.00.6001.19328">
  <style></style>
  <div><font face=3D"Arial" size=3D"2">Hi Stefan,</font></div>
  <div><font face=3D"Arial" size=3D"2">=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=
=A0=A0 Following Grahams
comments.</font></div>
  <div>=A0</div>
  <div><font face=3D"Arial" size=3D"2">1. What is the ground for you
antenna?</font></div>
  <div>=A0</div>
  <div><font face=3D"Arial" size=3D"2">2. Is the steel ladder/ frame
work=A0next to the antenna pole re-radiating any signals?</font></div>
  <div>=A0</div>
  <div><font face=3D"Arial" size=3D"2">Regards Edgar</font></div>
  <div><font face=3D"Arial" size=3D"2">Moonah, Tasmania.</font></div>
  <div><font face=3D"Arial" size=3D"2">=A0=A0=A0=A0=A0 </font></div>
</blockquote>
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