Hi Mal and others,

> On 2 August 2011 20:24, mal hamilton <[email protected]> wrote:
> Warren
> I do not have a problem. I can see es hear them all but I am disappointed
> how weak my signal looks on some of the EU grabbers compared to yester years
> and some cannot hear me when I call for a QSO.

It would be interesting to know if their reports of other Txs have changed over 
the same time. In other words, is it a change in their sensitivity (whether due 
to Ae change, pre-amp characteristics changing or whatever)?


> BUT I do not use Probes OR Small loops. I use what one would call normal
> LF/MF antennas.

On 2011 Aug 2, at 21:33, Gary - G4WGT wrote:

> Most grabbers do not use the main antenna, I have only one main antenna for 
> LF & MF so the grabber uses an active antenna

At LF the background noise is bad compared with HF/VHF/etc., so you can get 
away with a smaller antenna. Do the grabber operators do checks like this, e.g. 
switch between their active ant and a larger main ant and see if the SNR (as 
against the signal level) changes? If it doesn't, then their smaller ant is 
good enough. 
Perhaps some of the grabber operators would like to reply with their hints and 
kinks - personally I'm ignorant of how they run these things.


73,
Chris G4OKW

-----------------------
Dr Chris Trayner
School of Electronic & Electrical Engineering,
The University of Leeds,
Leeds LS2 9JT, United Kingdom
Tel: +44 113 34 32053
Fax: +44 113 34 32032