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From: MarkusVester@aol.com
Message-ID: <3cb.49282a5.31e0fa6d@aol.com>
Date: Sat, 8 Jul 2006 08:09:17 EDT
To: rsgb_lf_group@blacksheep.org
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Subject: Re: LF: QRM in Eastern Europe - vice versa?
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Dear LF,

another point worth mentioning is the possibility of interference from an 
amateur transmitter to a telecontrol receiver. 

In the period before 1 W ERP was generally permitted in Germany, a few of us 
were asked by the authorities to submit technical reports on our LF 
activities. One aspect I covered in some detail was potential interference to a dense 
population of DCF 39 receivers. It was shown that, assuming 40 to 50 dB 
selectivity in the 139 kHz receiver, this would be very unlikely beyond nearfield 
ranges of about 150 meters from the amateur. However a HA station transmitting 
near the lower band edge would be cochannel interference to a receiver on 135.6 
kHz. With 53 dB ERP difference and near the fringe of their coverage, it could 
potentially disrupt EFR service within a couple of kilometers.

73 
Markus, DF6NM

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<HTML><FONT FACE=3Darial,helvetica><HTML><FONT  SIZE=3D2 PTSIZE=3D10 FAMILY=
=3D"SANSSERIF" FACE=3D"Arial" LANG=3D"2">Dear LF,<BR>
<BR>
another point worth mentioning is the possibility of interference from an am=
ateur transmitter to a telecontrol receiver. <BR>
<BR>
In the period before 1 W ERP was generally permitted in Germany, a few of us=
 were asked by the authorities to submit technical reports on our LF activit=
ies. One aspect I covered in some detail was potential interference to a den=
se population of DCF 39 receivers. It was shown that, assuming 40 to 50 dB s=
electivity in the 139 kHz receiver, this would be very unlikely beyond nearf=
ield ranges of about 150 meters from the amateur. However a HA station trans=
mitting near the lower band edge would be cochannel interference to a receiv=
er on 135.6 kHz. With 53 dB ERP difference and near the fringe of their cove=
rage, it could potentially disrupt EFR service within a couple of kilometers=
.<BR>
<BR>
73 <BR>
Markus, DF6NM<BR>
</FONT></HTML>
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