04/01/2004 14:19:22, "hamilton mal" <[email protected]> wrote:
My suggestion is to use the mast as a support for a vertical arrangement.
Connect all horizontal wires regardless of configuration together at the top
of your 14 metre mast and use a vertical drop lead to connect to your
loading/matching coil. ie a top loaded vertical. Keep the drop wire about 1
metre out and away from the mast, the wire does not have to be exactly
vertical pull it out at the bottom end about 2 metres. I am assuming your
mast is earthed, if not use the mast as the vertical radiator with the top
wires connected directly to it at the top and feed the bottom end of mast to
the loading coil. Resonate the coil for your preferred frequency on 136 khz
and use a smaller coil at he bottom feed end in series to earth as a 50 ohm
matching device. Earth the coax braid and tap the coax centre conductor up a
few turns from earth to get the perfect match. A small call is preferable to
get an accurate match, tapping up the large coil from the bottom is too
coarse.
Hope this helps you but maybe you know all of this already hi
73 de Mal/G3KEV
Hi Mal,
Thanks for your reply & comments, most of the info I am already aware of, I was just
considering wether to feed at the centre of the inverted V (bow tie shape) or at one end of
the inverted V. I know its probably a case of "suck it & see" never-the-less I do appreciate
any-ones comments on the matter.
At the moment I am matching the coil with a transformer wound on a TV scan coil core with
10 turns pri & 20 turns tapped on sec & it gives me 1 : 1 match as far as my equipment
shows.
73
Gary - G4WGT
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