"'Geri' Kinzel, DK8KW" wrote:

Alberto    I2PHD,

Alberto, first of all thanks for providing ARGO, I have played around with
it and found it very useful.

About the coils on 9 kHz: I am using a u-shaped core with a closing bar on
top made of ferrite material (special thanks to Markus, DF6NM). Using this
setup I have a coil wit 1 H (one Henry) inductivity, lifting the ferrite
bar on top by means of a screw some tenth of a millimeter I can fine-tune
this coil between about 0.5 and 1 H. With 10 Watts output I achieve a
current of roughly 130 mA into my 18m vertical ... sufficient for about
770m distance ...

Hello Geri,
                  thanks.
Funny, the two extremes of the spectrum have the same problems of detection
of signals below the noise.
I was reading a couple of days ago about the experiments done by John K3PGP
using a modulated laser light, aimed at the sky.  He says that it was possible 
to
receive the scattered light and to recover the modulation at 25 km distance...
impressive.  This looks as another possible field where QRSS and/or DFCW
could be of help....

73   Alberto   I2PHD