Recently HamRadioSchool.com featured a story on flag pole antennas as a way to comply with neighborhood covenants, conditions, and restrictions, or CCRs, while still having good HF capability. This feature article describes another vertical ¼ wave antenna that works marvelously on the higher HF bands, that can go places with you for portable HF ops, and that won’t empty your checking account. Three of our young HamRadioSchool.com affiliates, Cole, Ethan, and David, show you how easily it can be done.
Cole’s “permanently installed” home HF station in our cursed covenant protected neighborhood employs a stealthy pine tree-mounted fan dipole to radiate nicely on 10m, 20m, and 40m. But we’ve been missing out on a lot of fun on some of those other higher HF bands… until recently. We’ve found another way around the neighborhood CCRs with a temporarily erected portable ¼ wave vertical. We used it today to make contacts from Minnesota to Switzerland with 100 watts on 10m and 17m bands, but it works just as fantastically on 12m, 15m, and 20m bands. Here’s the setup, and you can see it in the accompanying video, too.
Radiating Element: The radiating element is the MFJ-1979 stainless telescopic whip [~ $60]. It’s a pretty solid large extendable element that pulls out to 16.5 feet, so it’s effective down to 20m band without a tuner. It collapses down to just 27 inches, so it can also be used for everything up to 50 MHz and it stows away nicely. We tune it to a given band by simply extending or contracting it while measuring SWR with an analyzer, and it is also marked on the telescoping segments with permanent ink so we can zip quickly from one band extension to another without the analyzer hassle. Yes, it’s a little extra trouble compared to using a true multiband antenna or a tuner, but we can usually obtain 1.2:1 SWR or better with only a few seconds of finagling. Plus, we like to set up a station outdoors, at a scout camp, in the shade of the local pines, or just inside the garage within a few step of the well-stocked refrigerator, so it’s not too inconvenient to stroll over to the antenna to adjust it when we’re ready to switch bands.
Mounting Arrangement: The telescopic element fits into a High Sierra Jaws Antenna Mount [~ $35 ]. This is a really nicely designed antenna mount with an adjustable clamp that’ll hold firmly onto almost anything. It has a standard 3/8 – 24 thread female mount into which the MFJ-1979 fits and an SO-239 “UHF” connector on the opposite side. It also has a convenient hole drilled into the clamp body on the electrical ground side through which a screw can be used to attach ground radials. We like to have the Jaws clamp chomp down onto the wooden handle of a common dirt tamper. The tamper has a heavy, flat metal base that is more than sufficient to support the fully extended vertical element, and the Jaws clamp works nicely with the wooden handle. Plus it’s usually just hanging out in the garage and is conveniently portable. A fat stake driven into the earth will do just as well with the Jaws clamp.
Ground Radials: We use four bundles of home brewed ground radial wires, each bundle comprised of six wires soldered into a #10-12 ring terminal. Each of the four bundles spreads out into a quadrant of radials under the telescopic element, 24 radials total. The four ring terminals are stacked over the Jaws clamp ground connection hole and attached with a small stainless screw and nut. Each radial wire is about 16 feet long. We use a perimeter chord-length stick properly sized for the 15 degree angle subtended between radials (about 49 inches for 16’ radius), making it easy to evenly space the radial wires when spreading them along the ground. The wires are stored in coiled bundles, so we just use rocks or a small tent stake to keep them held out straight.
Set Up & Take Down: It usually requires about 10 – 15 minutes to set up the entire antenna, with the bulk of that time dedicated to unfurling, spreading, and anchoring the ground radial wires. We route about 40 feet of coax to the radio, typically outdoors as previously noted, or through a window to a comfortable operating location on cold days. Antenna deconstruction is even quicker – kick the rocks aside, collect the quadrant ground radial bundles at the antenna and roll them up, securing each with a zip tie. We leave them attached to the Jaws clamp ready to go for next time. Scrunching up the telescopic element and detaching it from the clamp is a breeze, and it all tucks away in moments.
Results: We’ve used this antenna several times in recent weeks at home and also with a portable station for Boy Scout Jamboree On The Air (JOTA) in October, each time with fantastic results. Today with nice F2 and sporadic E conditions we made many contacts into Europe and across North America with the 100 watts of a barefoot Yaesu FT-897D. This simple antenna gets us onto those “other bands” that we’ve been missing out on, 12m, 15m, and 17m, as well as the familiar 10m and 20m bands that the fan dipole and our scout rig’s end fed antennas deliver. Maybe we’ll catch you on some of those bands soon!
This antenna can be a great option for the ham in a CCR protected neighborhood with a quick and easy temporary installation that won’t attract a lot of attention. It also offers the convenience of portability, so it can be readily hauled to the local park, camp, forest or mountain location for relaxing outdoor operation. Be sure to view our video to get more insight about this terrific temporary antenna concept. Good luck with your station, and getting on the HF bands.
Cole WØCOL, Ethan KDØMFP, and David WØDTB