Re: LF: noise on VK and earth dipole tests

[Dimitrios Tsifakis <dtsifakis@gmail.com>]

Hi John,

2011/10/12 John Rabson <john.rabson@numeo.fr>:
> Amongst other things, it depends on the geology.  G3XBM has managed 5.6 km 
> with 5 W RF at very low frequency.  On 87 kHz with 4W SSB (cave radio) in 
> limestone, the best I know of is 1.6 km two way and 2.5 km one way in the 
> French alps.

Well, the S/N required for voice is much higher than that of QRSS30.
With a puny 3 W of RF and QRSS30 it seems I can cover a distance of
about 30 km and still have a S/N of 30 dB! Which implies that possibly
(if the signal received is normal ground wave, similar to that from an
above-ground antenna), with a spreading loss of 6 dB per doubling of
distance and with a bit more juice, much greater distances may be
covered.

> It is always worth trying.

That's the spirit in the amateur world of LF! :-)

73, Dimitris VK1SV