VLF,
Recently i've done a tour with the motorbike in the fields near my VLF
TX QTH JN49IS36VH
and suddenly saw that there is a big building lot and a deep hole into
the earth, just 10m distant where the loading coil was located in the
last 11 experiments. They will install a wind power plant there :-/ In
the newspaper they told about a 2 MW type. So this QTH seems to be
history :-( I have to seach for a new location close to the old since
my special permission is fixed to that hill. After driving around on
the hill i found a new suitable QTH.
The new QTH could be JN49IS44UH
about 1 km distant. As you can see on the map, there are 2 wind power
plants (600 kW, out of the early 90's) very close to the location. Most
usually the wind comes from SW and i only do experiments if the wind
comes from there. So the kite will not come to close to the rotor ;-).
Most probably the wind power plant has a superior eath system and i
could connect my VLF TX system to that! So i could get a higher ERP by
that, probably. I do not expect to high losses due to the presence of
the metallic tower since it is directly grounded and if my system will
be grounded to that, it will just add some C and some low additional
coil losses that will be overcompensated by the lower earth losses i
assume.
My 300m kite vertical has a measured C of about 1650 pF, i.e. i need
about 190 mH for resonating at 8970 Hz. The towers are just 60m high i
think, so rather a small stick compared to the antenna, just 20 % ;-)
and it is not resonant on that frequency...
Hope it will be successful on that QTH and no unexpected problems will
occur.
I plan the next experiment in August or September. Hope YOU will take
part :-)
73, Stefan/DK7FC
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