Message-ID: <14767.200102081422@gemini>
From: "James Moritz" <j.r.moritz@herts.ac.uk>
Organization: University of Hertfordshire
To: rsgb_lf_group@blacksheep.org
Date: Thu, 8 Feb 2001 14:26:18 +0000
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Subject: Re: LF: Loran Lines.
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Dear Martin and Group,

Most of the Loran noise seems to come from Lessay on the 
French coast, which is much nearer SE England than Wales, so 
one would expect the Loran noise to be relatively weak at your 
QTH. At my QTH (Hertfordshire), Loran is often the limiting factor  
on receive sensitivity when QRM/QRN is low. If Loran is not a 
factor, you should be able to hear a crackle of QRN, especially 
after dark. Perhaps the other GW stations could tell you what to 
expect.

A possible reason you are experiencing general lack of sensitivity 
might be receiver front-end overload. Most RXs just have a low-
pass front end filter for the LF/MF range, and the non-resonant 
antenna means your RX is being bombarded with LF and MF 
broadcast signals, and powerful LF commercial stations, all of 
which will be vastly stronger than tiny amateur signals, which 
consequently will get buried by assorted intermods, blocking, etc. If 
this is the case, tuning the antenna (as described by G4GVC in the 
LF handbook), or using a preselector, (G3YXM's design, for 
example) might improve the situation greatly.

Cheers, Jim Moritz
73 de M0BMU