john sexton wrote:
Hi Mal,
Instead of just pointing us to the library, can you be a little more
specific?
What are the key articles to read and what references would be sufficient
for the British Library to find them?
John.
Surf the net, also there has been several directives from SM and DL on this
medium pointing out what material is available and where to find it world
wide. One publication was a complete volume
of US army material covering every aspect of LF/MF
.
There is so much written about the subject those interested will have to do
their own research and browsing.
Each individual on LF will have a different approach and what works for one
will not work for another because of local environment, type of antenna,
ground radial system, coastal or inland qth, so many things, regardless what
the manual says.
My approach was to built a tx running a few hundred watts out, match
everything to 50 ohms, put a vertical antenna up as high as I could
reasonably get it, put down a good ground radial system, keep the antenna
tuning and matching inductor at the bottom of the vertical and run 50 ohm
coax to the shack which is 150 ft away, this avoids hight RF voltages and
radiation hazards in the shack.
This installation has been working well for around 2 years, is very stable
and only needs retuning if I change frequency. The weather seems to have
little effect on resonance ie sunshine or rain and my inductor/matching is
exposed to the elements and is wound with 2.5mm teflon insulated copper wire.
AVOID bringing the antenna wire directly into the shack, even though it might
be more convenient. for tuning purposes.
Keep the top loading horizontal wires and drop wire going to loading inductor
at base of mast TIGHT, this avoids them blowing about in the wind and going
off RESONANCE and possible damage your fet pa, due to high SWR.
Use good quality insulators, preferably the long ribbed stick glass, ceramic
or polythene type, and keep your antenna wires well away from buildings or
trees.
73 de MAL/G3KEV
John, G4CNN
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