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
2 weeks!
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
again.
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).
VY 73
Jacek / SQ5BPF
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