You might also consider receive noise, which you can check in both spots (unless you are planning a dedicated RX antenna). As others said, loss for most coax will be much lower than one dB per 100 feet.
Vic 4X6GP > On 13 Jul 2016, at 01:16, Dauer, Edward <[email protected]> wrote: > > So long as antenna discussions on the reflector haven’t been met with the > “OT” cloture lately, I have an antenna question of a different sort. I am > contemplating a ¼ wave vertical with four elevated radials for 80 meters. My > choices for siting it are two – one is near the top of the property (about > 8,600 feet ASL), somewhat in the clear, and within 100 feet from the > operating position. The other is in a meadow near the property boundary, > which is much more open and a just a bit higher – but it has two other > significant characteristics. One is that the land slopes away from that > site, over about half the compass from NNW to SSE, at a slope of 10 to 15% > for about a half mile. According to ON4UN’s text, that slope could give me a > significant gain in that part of the azimuth with no significant terrain > obstruction on the other half. The second characteristic, however, goes the > other way – that site would require about 500 feet of feedline from the house > to the antenna feed point. I have been looking at the loss factors in > hardline and in “direct burial” coax, which on 80 meters seem modest but not > irrelevant for a run of that length – maybe a dB or so per 100 feet. What I > can’t quantify – because I don’t have enough life expectancy to learn how to > adapt antenna modelling software to a Mac or even to learn it if I could – is > whether the gain from the sloping near field would make up for the feedline > loss. In case it matters, the ground likely has very poor conductivity. > It’s decomposed granite – a specialty in the Colorado mountains – with a very > thin layer of usually very dry soil. (Our well has a static level of 142 > feet, so there’s no ground water anywhere near the surface.) Anyone have > opinions, guesses, estimates, advice, or whatever – should I accept the > feedline losses and enjoy the half-hemisphere low-angle gain? Or would the > poor soil quality negate that advantage? > > Ted, KN1CBR > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
