On Thu, 16 Mar 2017, DK7FC wrote:
I'm already dancing on another party, the transmitter is running 'key-dwon'
since almost a week now. On the weekend there will be a
rain period but i want to risk to continue with the transmission, hoping there
will be no flash over. So far the idea is to run it for
Thus the antenna is booked for ULF over the weekend.
Could we try around 3053Hz after that? 3053 has 1/4 wavelength more at
around 900km distance. The reason is that i'm not sure we're well in the
far field region at this distance (we're way past 2 wavelengths, but maybe
we could still gain a few dB from this). If you transmit with an e-field
antenna, and the distance is N/4*wavelength where N is an uneven integer,
then i would have a better signal with a h-field antenna. Making the
distance in wavelengths 1/4 wavelength longer would change it into e-field
BTW this is probably the reason that most people didn't get further than
10km on 9kHz: they used the same kind of antenna (so with transmitting
with an e-field antenna, they would get better results with a h-field
antenna once they get near 1/4 wavelength, and vice versa).
Jacek / SQ5BPF