Hi all,
I'm about to put up a 136kHz Antenna and have a couple of questions.
I don't have much space in the garden, approx 20m from the apex of the
roof to a 20m high poplar tree in the opposite corner. I am considering
an offset 'T' with a multi-wire top.
I am assuming (within practical limits) that as much capacitance as
possible in the antenna is beneficial. It will resonate with lower
inductance and therefore lower resistive losses.
The RSGB LF experimenters h/b (p52) suggests that 2 wires separated by
100mm will provide 39% increase in capacitance. Is it safe to assume
that putting multiple wires up at 100mm will provide a compound
percentage increase? I am considering 6 wires at 100mm separation. Are
there any better solutions - I have neighbours I wish to remain on
speaking terms with...
What effect does height have on the antenna? I can fairly safely get the
antenna up to 10m above ground level without too much difficulty. Will
there be any significant benefit to raising the tree end of the antenna
to say 15m.
I will probably feed the aerial at about 5m from the house with two
coils, one at ground level and a second 2 litre coke bottle sized coil
at the junction between the vertical and the capacitive top.
Sorry for the newbie type questions. Getting this right first time is
important, neither the tree nor the apex of the house are particularly
easy to get at and I don't want to do it too many times...
73,
Martyn G0CZD
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