LAWRENCE MAYHEAD wrote:

 OK Mal, but from the Rx point of view a strong signal is not important so long as it is enough to overcome reciever noise surely?
Lawerence. I am not offended. I like a good discussion as long as it is based on a  sound fundation but there is a lot of nonsense discussed on this medium. You do not always get enough signal from small loops and low horizontal wires. A german station published some figures the other day and where his vertical gave a signal strength of some 30uv the loop was 0.25 uv and this was a loud commercial station.  The majority of amateur stations transmitting on 137 khz would not have been heard by him on his loop. I have tried this on 160 metres using a 40 metre vertical quad loop resonated for 160m and compared it to my inv L up at 100 ft.
On short/medium haul up to say 2000 miles the loop was good but beyond that for the far east, Malaysia/Australia/Japan etc I could not even hear the signals, whereas the signals on the inv L were perfectly readable. The loop was pointing in the correct direction.
On LF for a few hundred miles a loop will probably give some results but when looking at say 3000 k/metres and beyond it is doubtful and for TX useless.
When GW4ALG uses his loop I can barely hear him. When he switches to 60ft vertical 589. When G6RO was using a loop he was at best 559 with qsb and now he has changed to a vertical he is 599. It speaks for itself.
73 de Mal/G3KEV

It seems to me that what is important is sig/noise ratio and this depends not so much on the capture area  but more on the elevation angle,directivity etc. I also have experimented over the years  and am constantly amazed at what there is to be discovered,not the least on LF where many things are different especially the effects of ground.Anyway my remarks were not meant to be critical,they were intended to be constructive and I hope you have not taken offence.73s Laurie.