I'm brainstorming methods of mounting an EFHW. Unfortunately, I have no trees, so I'm considering a horizontal gutter mount which would afford me about 70 feet. Is this workable or should I consider a telescopic mast like a spiderbeam instead?
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1$\begingroup$ Hello Alan, and welcome to ham.stackexchange.com! Please tell us more about your idea of the gutter mount. Do you mean that you're thinking about attaching the antenna to the gutter of a house? $\endgroup$– rclocher3Nov 19, 2020 at 15:52
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$\begingroup$ Exactly that. Clips are available to attach antenna wire to the gutter for a horizontal run. $\endgroup$– AlanNov 20, 2020 at 6:09
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1$\begingroup$ @F.Sessink you should expand your comments a bit and make them an answer. $\endgroup$– rclocher3Nov 20, 2020 at 19:47
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1$\begingroup$ @alan Are we assuming a non-metallic gutter? I always thought that (metal) gutters seriously interfere with horizontal antennas. $\endgroup$– GalaxyNov 21, 2020 at 1:43
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1$\begingroup$ @F.Sessink Answered my question, I don't think I'll proceed further with this idea. If he posts his comment as a answer I'll accept it. Thanks all! $\endgroup$– AlanNov 21, 2020 at 13:11
2 Answers
My gutter antenna experiments revealed that the gutter (metal of course!) itself can be used as end-fed half-wave antenna on the self resonance frequency. The efficiency is poor: the losses to conducting environment are very high, even with dry weather.
For reception such antenna can be used, but all the interference generated in the house is coupled to the antenna: the counterpoise is electrically polluted and this interference is in series with the received signal. When used as TX antenna the losses are high and the impedance must be matched to off-resonance frequencies.
Even with a poor antenna it is possible to make radio contacts. When possible: use a separate wire with a resonating length and then the end of the antenna must be spaced from the gutter: the antenna wire coupling to the gutter must be as low as possible.
One of my experiments was a sloped half wave, starting anywhere in the middle of the gutter, and the gutter metal used as ground/counterpoise. The other end of the half wave (also a quarter wave works fine) free hanging to its end, only two meters high. With 10 meters wire and 10 watt power I had SSB QSO's with Canada an USA on 14 MHz.
For RX: the induced noise from all electric interference generated in my home is present in the counterpoise (ground if you want to call it). In the same dimensions it must be possible to make a dipole with lower losses and lower interference when receiving. That is preferred. PA0FSB
As you are talking about the guttering I can imagine you may well then have access to a loft area. If so, Consider an end fed wire installed as high as possible, in this space, then zig zag to get a little extra length, run it into a SG239 smart tuner and feed the coaxial down to your transceiver. Hey ho! it works! Problem is an SG239 is expensive to purchase new, but I managed to find a secondhand one!
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$\begingroup$ Manual antenna tuners work well also, and are considerably less expensive. $\endgroup$ Nov 23, 2020 at 18:30