Simple Ham Radio Antennas

According to Edward M. Noll (W3FQJ), "The 5/8-wavelength vertical is a preferred length for the best low angle radiation."  For the higher HF bands (20 through 10 meters), this antenna is easily assembled and requires a small quantity of wire, some ceramic insulators, a suitable mast, 50-ohm feed line or 450-ohm feed line, a simple ground radial system, and a sturdy antenna matchbox or ATU .  Multiband use between 20 and 10 meters is possible with 450-ohm ladder line , ATU, and a balun, while good single band use can be obtained with 50-ohm coaxial cable and an inline or base antenna "tuner". So, let's build a simple 5/8 wavelength vertical for the 10 meter amateur radio band, centering on 28.4 MHz .  This frequency is at the mid-point of the SSB allocation for Technician Class licensees.  The antenna was built at my new home in the Puna District on 18 April 2014. MATERIALS: Using the general formula, 585/f (MHz)=L (ft), our vertical element will measur

Over the past few posts, I've been describing some of the antennas I designed, built, and used during my days as a novice amateur radio operator (1977-1978).  Most of the working designs were copied into school theme books and saved for future reference. One of my favorite homebrewed antennas was a simple vertical  antenna supported by a high tree limb terminating with a slightly angled ground plane consisting of 10 radials.  The antenna was designed for 40 meters and worked very well for contacts throughout the Pacific Rim and the mainland United States . Last weekend, I decided to duplicate that antenna with some spare wire, ceramic insulators, coaxial cable , and basic tools. As mentioned earlier, the process of moving to a new home often uncovers items you once thought were lost.  Such was the case here when I found several 50-ft /15.24 meters rolls of #14 AWG house wire in the garage.  That wire would serve as the vertical element and the rudimentary ground radial sys

Building wire antennas is one of the few amateur radio activities that remains fairly inexpensive.  Your nearest hardware store or home improvement outlet is chocked full of wire, connectors, pvc pipe, copper tubing, and basic tools to launch your antenna building efforts. Whether you make simple dipoles, inverted vees, loops, or even directional vertical arrays, the satisfaction of having built something that links you to your fellow amateurs around the world is beyond compare.  If the antenna doesn't meet your expectations, you can salvage most of your material and try again.  It's all part of a continuing educational experience that can last a lifetime.  Add to this mix a few simple transceiver kits or accessories and you have something that will be your faithful radio companion for many years. I approach my antenna "adventures" with that sort of mindset, and I'm always on the lookout for intriguing antenna ideas that I can modify for my own use. Such wa

Like many amateur radio operators, I've collected many boxes of electronic parts, various lengths of coaxial cable , and assorted rigs over the past 38 years.  I suppose my "shack" is testament to my "pack rat" tendencies.  I rationalize this collective habit by saying all of this material will become useful some day.  That some day was Thursday, 13 March 2014.  I had several lengths of RG-58 coaxial cable that had seen better days.  The assorted 100-ft/30.48 meters and 50-ft/15.24 meters lengths were gathering dust in the corner of the garage serving as the storeroom for my radio room.  The connectors were in good shape and the vinyl covering was intact, although a bit grey from sun exposure.  I wanted to find a use for the old cable ,now that it had been "retired" from active service. Why not use the old coax as a low noise receiving antenna for 80 meters, which was a very noisy band even in my remodeled home in the Puna District of Hawaii Islan

A few days ago I read a fascinating antenna article by Cecil Moore (W5DXP) on the http://www.eham.net website.  Cecil described what he called a " Multi-Band 33-ft dipole" that works on 20, 17, 15, and 10 meters without an antenna "tuner" (i.e. transmatch ).  The secret to this outstanding antenna was the use of 450 ohm ladder line in conjunction with a series of switches and relays that selected the proper length of ladder line used to feed the antenna.  Depending on the band of use, Cecil could insert and remove sections of ladder line with his relay/switch system so that swr across his chosen band remained low.  By carefully selecting which section of feed line to add or subtract, he got a decent performing antenna without having to resort to a transmatch or "tuner." Cecil's idea got me thinking of ways to improve the dipoles I'm using at my new home site.  Although his idea has a lot of merit, I felt the need to build something a bit simpl

The sloping 1/2 wavelength dipole is one of my favorite antennas.  "Slopers" are good antennas for restricted space areas.  They are simple to build, inexpensive, and exhibit some directivity in the your chosen direction. According to VK6YSF, VE2DPE, and other amateur radio operators, a properly designed 1/2 wavelength sloper radiates energy at low angles relative to the horizon with vertical polarization.  Slopers don't require a ground radial system and can be fed with a good grade of 50 ohm coaxial cable.  A sloper antenna only requires one tall support (tree, mast, edge of a roof, etc.) and occupies less space that a 1/2 wavelength horizontal dipole. So, let's build one of these simple, effective antennas for the 10 meter band , centering on 28.4 MHz --right in the middle of the techncian class phone band. MATERIALS: One tall support.  In my case, I used a 33-ft/10.06 meter MFJ telescoping fiberglass mast.. One 5-ft/1.52 meter wooden stake to support

The "classic" W3EDP antenna has been around since March 1936 when Yardley Beers (W3AWH/W0JF) described a multiband antenna built by his friend H.G. Siegel (W3EDP).  Siegel used the traditional method of "cut and try" to arrive at an antenna length that would work satisfactorily on 160, 80, 40, 20, and 10 meters. Beers remembered that "A length of 84 feet (25.60 meters) seemed to stand out as being the best of all the combinations tried."  A similar "test and tune" method was used to determine a satisfactory counterpoise length of 17 feet (5.18 meters), "as the one working best in combination with the antenna." Since that time, several variations of this true "Zepp" antenna have been developed to facilitate portable, emergency, and even home use.  Many QRP enthusiasts use some kind of W3EDP-derived antenna for their operations.  The W3EDP antenna is a simple, cheap, and field deployable.  The antenna requires a 1:1 or 4:1

Over the past few years, I've built a variety of HF antennas for my amateur radio station.  All of my verticals, inverted vees, dipoles, and loops have been a learning experience, especially when I've been faced with limited resources and space.  Operating from an apartment or a home governed by CC&Rs and HOAs has been a challenge. Now that I'm slowly moving into a full acre of space in the rural Puna District of Hawaii Island, my space restrictions are gone and there are no committees to oversee my antenna activities.  I count this as a definite blessing.  For the first time in many years, I can build full sized dipoles, verticals with a decent ground system, and large full-wave loop antennas without interference.  Since my new property is surrounded by tall trees approaching 50 feet/15.24 meters, my antennas are well shielded from prying eyes.  When I operate out of my rental home in Laupahoehoe, I'm still hemmed in by utility poles and neighbors.  My antenna

Over the past 37 years as a licensed amateur operator, I've accumulated a wide variety of antenna reference material, including books, magazine articles, and topics discussed on amateur radio forums.  All ARRL members can further augment their antenna research by accessing the digital files of " QST ", the offical journal of the ARRL.  All told, there is an almost endless resource of antenna building ideas for most every ham station. Recently, I began to put some of these "classic ideas" to use on my new property in the Puna District of Hawaii Island .  I now have an acre of space to "plant" my antenna "farm"--quite a change from my present rental home which is hemmed in by neighbors and utility poles.  Although my neighbors have been tolerant of my amateur radio pursuits, I try to keep a low profile.  Namely, my verticals and inverted vees are usually lowered when they are not in use and, because of my part-time employment as a sports an

So far, the "tunerless" antennas I've built have worked very well.  They have been made with locally available materials from my "junk" box, neighborhood garage sales, and the nearby Ace Hardware Store.  These antennas have consisted of individual dipoles/inverted vees for my bands of preference (40, 20, 15, 10 meters), telescoping fiberglass masts (33-ft/10.06 meters tall), a single RG -8X coaxial feed line , and supporting wooden stakes or tree branches. Dipoles for each band were built on the ground and were later hoisted into position via a halyard and pulley system.  A "choke balun" made from part of the RG-8X feed line was attached to the mast just below the center connector at the top of the mast. In my first multiband antenna system, I changed bands by lowering and raising the appropriate antenna into place.  I couldn't change bands by staying in the shack. My second system was a modified "fan dipole/inverted vee" using mul

In some of my previous posts, I've investigated, built, and used multiband dipole and inverted vees using a single 50 ohm coaxial feed line .  With a telescoping fiberglass mast (33-ft/10.06 meters extended), a simple halyard and pulley system, and separate antennas cut for each band of use (40, 20, 15, and 10 meters), I've been able to change bands fairly quickly by lowering the dipole/inverted vee elements, substituting those of another band, and raising the new antenna.  With each band element cut for the desired frequency, the efficiency is high with low swr for that band.  Since each antenna element is trimmed for the lowest swr at my mast location, an antenna transmatch isn't necessary.  Sometimes, as in the case with the 40 meter dipole/inverted vee, an antenna cut for the cw portion of the 7 MHz band will often work well on the phone portion of 15 meters (21 MHz band). The 15 meter band will operate on the third harmonic of the 40 meter band . In order to save