Message-ID: <BLU146-W2792019561B0E93333EFC2CFF40@phx.gbl>
From: Laurence BY3A-KL1X China <hellozerohellozero@hotmail.com>
To: <rsgb_lf_group@blacksheep.org>
Date: Sat, 29 Aug 2009 02:06:27 -0800
Importance: Normal
MIME-Version: 1.0
Content-Type: multipart/alternative;
	boundary="_65a20fbc-2de8-4333-80d3-339fffdbded6_"
Subject: LF: Tree mixing
Sender: owner-rsgb_lf_group@blacksheep.org
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org


--_65a20fbc-2de8-4333-80d3-339fffdbded6_
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable


=20

Sorry this is way off topic in relation to noise generation at LF/MF but=
 I know of one case (as I was the responsible investigating engineer for=
 a well known .gov dept at the time) of a tree causing non intentional rad=
iation as a result of mixing of 45Mhz TV signals from Old Meldrum and a ne=
arby "lowband" FM transmitter  in Aberdeenshire - the resultant non linear=
 (arent they all) mixing process from this Horse Chestnut tree (and it was=
 the only one in the line of fire) caused  wobbly FM interference to a "fi=
xed High band service" -=20

=20

the Tree in question was about 5 miles from the TV transmitter on a ridge=
 and a couple from the VHF transmitter. The interfered with rx source was=
 some 100m from the Chestnut tree - It was confirmed that the interference=
 was coming from the mid section about 5 metres from ground level - a case=
 of the Bark being worse than the byte.  Ill leave you to guess how I clea=
red the problem.

=20

Its the only one and only kind I came across with during my career and I=
 couldnt really believe what the test equipment was showing - but it was=
 - we didnt go interalia the causes and bio-causes of such an effect but=
 it did exist - honest gov.

=20

youll know my respect for the globally dispersed Acacia tree and how marve=
llous it is as enhancer of LF signals wrt probes - so perhaps the trees sp=
eak more than we really think at RF...

=20

Laurence

_________________________________________________________________
With Windows Live, you can organize, edit, and share your photos.
http://www.windowslive.com/Desktop/PhotoGallery=3D

--_65a20fbc-2de8-4333-80d3-339fffdbded6_
Content-Type: text/html; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

<html>
<head>
<style>
.hmmessage P
{
margin:0px;
padding:0px
}
body.hmmessage
{
font-size: 10pt;
font-family:Verdana
}
</style>
</head>
<body class=3D'hmmessage'>
&nbsp;<BR>
Sorry this is way off topic in relation to noise generation at LF/MF but=
 I know of one case (as I was the responsible investigating engineer for=
 a well known .gov dept at the time) of a tree causing non intentional rad=
iation as a result of mixing of 45Mhz TV signals from Old Meldrum and a ne=
arby&nbsp;"lowband"&nbsp;FM transmitter&nbsp; in Aberdeenshire - the resul=
tant non linear (arent they all)&nbsp;mixing process from this Horse Chest=
nut tree (and it was the only one in the line of fire) caused&nbsp; wobbly=
&nbsp;FM interference to a "fixed High band service" - <BR>
&nbsp;<BR>
the Tree in question was about 5 miles from the TV transmitter on a ridge=
 and a couple from the VHF transmitter. The interfered with rx source was=
 some 100m from the Chestnut tree - It was confirmed that the interference=
 was coming from the mid section about 5 metres from ground level - a case=
 of the Bark being worse than the byte.&nbsp; Ill leave you to guess how=
 I cleared the problem.<BR>
&nbsp;<BR>
Its the only one and only kind I came across with during my career and I=
 couldnt really believe what the test equipment was showing - but it was=
 - we didnt go interalia the causes and bio-causes of such an effect but=
 it did exist - honest gov.<BR>
&nbsp;<BR>
youll know my respect for the globally dispersed Acacia tree and how marve=
llous it is as enhancer of LF signals wrt probes - so perhaps the trees sp=
eak more than we really think at RF...<BR>
&nbsp;<BR>
Laurence<BR><br /><hr />With Windows Live, you can organize, edit, and sha=
re your photos. <a href=3D'http://www.windowslive.com/Desktop/PhotoGallery=
' target=3D'_new'>Click here.</a></body>
</html>=3D

--_65a20fbc-2de8-4333-80d3-339fffdbded6_--