Venting

While I’m fairly happy with the performance that I get from my first HF antenna, an MFJ-2299 telescoping rotatable dipole, which consists of an MFJ-347 mount with a pair of 16.9′ telescoping stainless steel whips which will cover from 6m-20m, mounted on an MFJ-1921 tripod, with a DXE 25′ telescoping fiberglass mast, I wanted to have an antenna that covered the lower bands, especially 40m, as well as 80m and 30m, which the MFJ-2299 does not cover. I live in a small neighborhood in a suburb of Denver, Colorado, and have a very small lot, so stringing up 120′ of wire isn’t really an option. It’s also a new neighborhood, so the trees are all quite small, so I don’t have anything to use to get a wire antenna up in the air, nor to camouflage a stealth antenna. After doing quite a bit of research, including reading the ARRL book on “Small Antennas for Small Spaces” it seemed that the “unsung hero” of limited space may be the Magnetic Loop Antenna (MLA), or Small Transmitting Loop. A magnetic loop antenna for amateur radio is typically made of about 10′ of large diameter coaxial cable (utilizing the braided shield rather than the center conductor) which makes about a 1m diameter loop, connected to a tuning capacitor at the bottom. A smaller inductively-coupled loop is connected to the transceiver. The capacitor can be adjusted to change the resonant frequency of the loop. An MLA doesn’t need to be mounted very high, only 1-2m, […]