Hi Vic, Please also consider the current "MAG LOOP ANTENNAS" thread on this list which fits your requirements as long as the loop is big enough (2 to 3m in diameter at least).
73, Christian F1GWR Le 22 janv. 2017 à 13:34, Vic Rosenthal 4X6GP a écrit : > Today I am limited to the bands from 7 MHz and up and I want to get on 80m. > My space is very limited, and in particular (due to the need to rotate my > existing dipole), there is no way to put up a vertical more than about 3m > high, and no room for radials longer than a few meters. > > But the location is 35m above the ground and it is possible to add another > rotatable horizontal dipole to my mast. > > So I am thinking about a 6m long dipole made of aluminum tubing. I have some > that is about 20mm in diameter. I will make capacity hats for each side to > add some end loading. > > Yes, I know the bandwidth would be very narrow. But I could live with a 3:1 > SWR bandwidth of 30 kHz. > > > I'm thinking about two possible configurations for loading coils: one coil in > the middle, or two coils, each about halfway down each side of the dipole. > > I know that two coils would produce a more efficient antenna. But the one > coil in the middle has two big advantages: it would allow me to feed the > antenna via an isolated link, which would solve the common-mode problem > without requiring a balun, and it would allow for easy tuning and matching. > > So what do you antenna experts think? One or two coils? Or is it just crazy > to expect anything from such a short antenna? > -- > 73, > Vic, 4X6GP > Rehovot, Israel > Formerly K2VCO > http://www.qsl.net/k2vco/ ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
