I found some interesting documents concerning FS measurements on 300 kHz at the
website of ITS, Boulder, Colorado (Institute for Telecommunications Sciences).
In the summary:
"The dependence of field strength with distance from the transmitter is in good
agreement with the predictions of propagation models in the absence of irregular
I have made some more measurements which are published on my home page. There is still a
5-6 dB discrepancy between calculated and measured values. Next step will be to improve
the radial system with lengths of chicken net near the antenna base + ordinary radials
and see what happens with the "missing dB's".
( http://home5.swipnet.se/~w-54761/fs.htm )