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"Steve (another one)" wrote: Dear all May I pick-up on something mentioned in response to my earlier question. It was suggested that running a wire up a kevlar backstay is a simple soultion and avoids having to insulate a piece of conventional rigging. This sounds very sensible to me and plan to try it, it avoids having to mess with exposed connections to a wire backstay. However then Bruce in alaska said: Then just helical wrap the antenna wire around the Kevlar Backstay and have a really nice "Fully Loaded Antenna with alot of electrical length...... Could someone (Bruce perhaps?) explain this. Would I gain performance by simply wrapping the wire ? Is no of turns per length of backstay critical ? Is 'core' diameter critical ? Thanks Steve Gary has a valid point in that a tightly wound helical wire will tend to trap out the higher frequencies in the HF range. One thing to remeber however, is that if the band is open it doesn't take as efficent of antenna to communicate on these Higher Frequencies, and if the band is closed, no amount of antenna tuning or fooling around is going to allow communications. Where as on MF Frequencies, one needs all the length one can get for an efficent antenna, and the band is what it is, and really doesn't change much as far as open or closed, except for Day and Night. Better distances at night than during the day. A good compromise would seem to be a resonate 1/4 Wave at say 3200 Khz would allow for far efficency at 2182 Khz, by wrapping the helical windings tighter at the top of the antenna, give a reasonable length of wire on the lower part to resonate with the tuner at 12 Mhz, 16 Mhz, and 22 Mhz. Bruce in alaska -- add a 2 before @ |
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