When I went to Easter Island last year, I took with me a Ramsey active antenna based on a 5/8" x 6" ferrite rod. The Ramsey PR bragged about its Faraday shielding and the fact that the antenna operated in the magnetic realm, isolated from most urban, man-made noise. I bought the thing to use during my time in Santiago, Chile, knowing full well the reputation of older Latin American cities as being RF noise swamps. Santiago was a wonderful city (I want to go back) but the radio dial was just as advertised.... constant S-9 noise from the power grid and other stuff. The Ramsey antenna was a real revelation.... it worked like a bandit and I was able to DX, almost noise-free.

On the way home, I had to tear the antenna apart to rid myself of the PVC housing (another story). The shielding was simply a rectangle of aluminum foil laid on the coil and bar, with a 1/8" gap running longitudinally down the bar. An electrical connection to the ground plane of the little amp/control box and thence to the radio was made by a paper clip inserted under the foil, with the ground wire soldered to the paper clip. There was probably a piece of paper as insulation between the foil and the bar.

That was my first experience with a shielded loop antenna and there was a lot to love about it in an urban environment. Are we missing a bet by not shielding our external bars, even if they are a Booster Bar??????

John B.













John B.
Stillwater, Oklahoma, USA
Rcvrs: WiNRADiO 313e, Eton e1, NRD-535(kiwa-mods)
Antennas: 700' NE/SW mini-Bev, Wellbrook Phased Array (pre-production version)