Showing posts with the label Antennas

Antennas, Radiation Patterns, Baluns, and SWR for Beginners. Post 1823.

If you can't see the video, please insert this title URL into your browser search box: This simple, direct tutorial from"Amateur Radio World" covers most of the basic antenna concepts, including elementary antenna theory, various radiation patterns, the use of baluns, and SWR.  The explanations are clear and well illustrated. This video should be part of any introductory amateur/ham radio license course.  Perhaps the video would have been a bit easier to understand if the producers used both the traditional "foot-pound" and SI (metric system) antenna formulas. For the latest Amateur/Ham Radio news and information, please visit these websites: (a weekly podcast which is updated each Friday afternoon). ht

Simple Ham Radio Antennas--5/8 wave J-pole antenna for 145 MHz. Post #398.

If you have difficulty viewing this video, please insert this title link into your browser: Pityu Nagy (YO6PNQ) has assembled a beautiful and effective 2-meter J-Pole antenna from some copper tubing, a steel wire from a CB mobile antenna, some PVC pipe sections, and some parts from his shack. His loading coil at the base of the antenna is quite interesting. If you have some simple tools and access to a home improvement or hardware store, you should be able to assemble this antenna for whatever portion of 2-meters most suits your purpose. This antenna has a low angle of radiation (around 16-degrees) and should exhibit a gain over a 1/4 whip of about 3dB. Have fun! For the latest Amateur Radio news and events, please check out the blog sidebar. These news feeds are updated daily. You can follow our blog community with a free e-mail subscription or by tapping into the blog RSS feed. Thanks for joining us today! Aloha es 73 de Russ (KH6JRM). KH6JRM'

Simple Ham Radio Antennas: Broad Bandwidth Ham Radio Antenna Demonstration. Post #363.

A fun and not necessarily "scientific" demonstration on how larger diameter radiating elements of an antenna will provide wider bandwidth coverage. To keep weight and structure support under control, Larry (WD0AKX) chose the 2-meter band for his fascinating experiment. Using a frequency of 147.861 MHz as the design frequency, Larry makes antenna elements ranging from 1/16-inch to 3-inches in diameter to test his theory. His rudimentary tests confirm that larger diameter antenna elements do widen the bandwidth a bit on 2-meters. The same principle applies to HF operation, where classic "cage" dipoles, folded dipoles made from 300-ohm tv ribbon line, and fan dipoles often are used to broaden bandwidth. Overall, the video is well done and shows how simple antennas can be improved with just a few simple tools and instruments. If the video doesn't cue up immediately, direct your browser to: You can also enter the title directly to ge

Simple Ham Radio Antennas: Multiband HF Stealth Vertical Antenna Run-through. Post #359

A very simple, stealth antenna that produces good results without being seen by nosey neighbors. Basically, Tony has built a 3-band vertical with all elements connected to a single SO-239 connector and a radial ground system. Tony's antenna resembles a vertical fan dipole, with the radial system supplying the "missing half" of the antenna. I've built several antennas following Tony's basic design. They all work very well and no one in the neighborhood knows the antennas are there. Of course, there are tradeoffs. This antenna won't bust a pileup or get you 59+ reports all the time. But it does work. And, sometimes that's all you need to get on the air without being noticed by the HOA/CC&R "police." Good luck! For the latest Amateur Radio news and events, please check out the blog sidebars. These news feeds are updated daily. For more Amateur Radio news, please visit my news site at Thanks for joining us today!

Simple Ham Radio Antennas: How Antenna Tuners Work - KK4WW & N4USA. Post #351

This is an excellent antenna tuner tutorial from Gaynell Larson (KK4WW) and Dave Larson (N4USA). Dave covers all the basics, including SWR, basic tuner design, and proper use of antenna tuners. This video is a useful addition to your Amateur Radio Library. While it's possible to make antennas that don't require some kind of system to match the antenna impedance to your rig's impedance, most amateur radio operators I know use antenna transmatches ("tuners") to provide the best possible match between rig and antenna. This is especially important if the antenna is used for several amateur radio bands. The use of an antenna tuner is required if you use balanced feed lines, such as 450 ohm ladder line, 300 ohm television twin lead, or homebrewed balanced feed lines. A balanced tuner will do the job of matching antenna to rig. You could also run your balanced feed line into a 4:1 balun and then onto your tuner with a small length of 50 ohm coaxial cable, such a

Graphene-Based Nano-Antennas May Enable Networks of Tiny Machines - Department of Electrical Engineering. Post #350

Graphene-Based Nano-Antennas May Enable Networks of Tiny Machines - Department of Electrical Engineering : "Graphene-Based Nano-Antennas May Enable Networks of Tiny Machines Networks of nanometer-scale machines offer exciting potential applications in medicine, industry, environmental protection and defense, but until now there’s been one very small problem: the limited capability of nanoscale antennas fabricated from traditional metallic components. Assistant Professor Josep Jornet's research with his advisor, Professor Ian Akyildiz on graphene based nano antennas has been featured by the Science andTechnology News Center of Georgia Tech. The project shows that "the concept of graphene-based nano-antennas is feasible, especially when taking into account very accurate models of electron transport in graphene. Many challenges remain open, but this is a first step toward creating advanced nanomachines with many applications in the biomedical, environmental, industri

Simple Ham Radio Antennas: Antenna Fundamentals 2 Directivity. Post #347

This video is part of a Royal Canadian Air Force Training Film series produced by the National Film Board of Canada. Thanks to Javier Anderson for the tip. This classic film, most likely produced in the mid to late 1950s, does an excellent job of explaining important reception basics when using a radio. This series of videos would make an excellent feature for Amateur Radio License Classes. The dialogue is direct, uncomplicated, and thoroughly understandable. Great video. For the latest Amateur Radio News and Events, please check out the blog sidebars. These news feeds are updated daily. You can follow our blog community with a free email subscription or by tapping into the blog RSS feed. If you want more Amateur Radio news, please visit my news site at Thanks for joining us today! Aloha es 73 de Russ (KH6JRM).

Simple Ham Radio Antennas: A Ham Radio 10 meter ground plane antenna. Post #311.

Another great video tutorial from antenna guru Dave Tadlock. This time, Dave designs, builds, and uses a simple ground plane antenna for 10 meters. Although Dave says his design can be ground mounted, a true ground plane antenna is always elevated to decouple the radials from the actual ground to eliminate ground losses. Dave's instructions are clear, precise, and often humorous. I've built several ground plane antennas following Dave's lead. The hardest of the lot was for 40 meters. In order to get the radial system off the ground, I had to use a slingshot and a length of weighted nylon rope to shoot the vertical element to a branch about 40 ft/12.19 meters above ground. With the bottom of the vertical element at 7 ft/2.13 meters above ground, it was easy to attach four, sloping quarter wave radials to the coax connector and tie them off at pre-positioned stakes. It's a lot easier to build a 10 meter ground plane. If you chose a frequency of 28.400 MHz (in t

Simple Ham Radio Antennas: The Extended Double Zepp Antenna. Post #304

This historical amateur radio antenna is becoming a bit more popular these days because it delivers modest gain over a horizontal dipole (about 3 dB) and is simple to build. This video by Stan Gibilisco covers all of the basics of this antenna and its construction. While it is perhaps best to use two supporting masts for the antenna, it can work reasonably well configured as an inverted vee. According to Stan, the EDZ antenna is basically "a collinear array of two 5/8 waves in phase." So, each antenna element will be a bit longer than the dipole most of us are accustomed to building. Also, the usual dipole formula, 468/f(MHz), doesn't apply here. After consulting several texts and antenna books, I chose to use the formula 585/f(MHz) for my EDZ Antenna. My last EDZ was cut for 20 meters and it worked very well. This time around, my property is a bit larger and I thought a 40 meter EDZ configured as an inverted vee would fit within my property without being seen by

Simple Ham Radio Antennas. An 80-10 Meter Field Day Inverted Vee Antenna. Post #282

ARRL Field Day is right around the proverbial corner--28 June to 29 June 2014, to be exact.  According to the ARRL, more than 35,000 amateur radio operators used 2,500 emergency-powered stations to get on the air in 2013.   A similar number is expected this year. While many of our fellow amateurs will be heading to a Field Day site, there are a few of us, including yours truly, who will be operating under emergency conditions at home as 1E stations or as mobile stations as 1C.  For those of us home bound or forced by HOAs or CC & Rs to "hit the road" during Field Day, this national emergency communications exercise can be just as much fun and instructive as showing up a your club site. Before I retired from the commercial broadcast business, I usually worked Saturdays and Sundays in the news room, doing play by play over the radio, or hosting remote broadcasts from shopping malls and craft fairs.  Great work and lots of crazy people, but I often missed a chance to

Simple Ham Radio Antennas. A 5/8 wavelength vertical antenna for 20 meters. Post #274

How would you like to have a simple, effective antenna for 20 meters thast will give you some gain over a ground plane antenna and exhibit a radiation angle of approximately 15 degrees? You can grab more DX (distance) at a modest cost by building a 5/8 wavelength vertical antenna working in conjunction with 1/4 wavelength radials beneath the main radiating element. I've built 5/8 wavelength antennas for 10 and 15 meters and they work very well.  If you desire multiband performance out of this antenna, you will need a balanced feed line (such as 450-ohm ladder line), a 4:1 current balun, and a sturdy ATU ( antenna tuning unit ).  If you prefer to use this antenna on one band only, you can establish resonance with a base loading coil that tunes the antenna to 3/4 wavelength  resonance.  Standard 1/4 wavelength wire radials are used with both versions of this antenna. According to William I. Orr (W6SAI) and Stuart D. Cowan (W2LX), "a 5/8 wavelength antenna provides imp

Simple Ham Radio Antennas: The Ghost of Antennas Past--the simple vertical. Post #269

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

Simple Ham Radio Antennas: "The Poor Man's Beverage" Antenna. Post #265

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

Simple Ham Radio Antennas: Sam's "James Bond" Antenna. Post #264

Whenever I get a day off from my substitute teaching duties, I try to attend meetings of the Hawaii QRP Club at the Hilo, Hawaii Jack In The Box Restaurant.  The meetings usually last from 0600 to 0900 local time and cover a variety of topics, from antennas to homebrewed equipment.  Attendance varies from to 2 to 7 or 8 persons, depending on who's working or free for the day.  Dean Manley (KH6B) usually brings some of his antenna notebooks and his vast storehouse of experience as a radio broadcast engineer to the meetings.  There's always something interesting or new at these gatherings. Recently, some of us have been discussing homebrewed antennas that can be operated from areas restricted by HOAs, CC&Rs , or just plain lack of space.  One of the most intriguing antenna ideas came from the late Sam Kumukahi (KH6AFS), who, during the 1990s, used what he called a "James Bond" antenna with excellent results for local and occasional DX contacts.  At the 27 Febr

Simple Ham Radio Antennas: The W3EDP antenna revisited. Post #261

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

Simple Ham Antennas: The AG9C Loop Antenna. Post #258

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

Simple Ham Radio Antennas: Antennas without tuners, part 4. Post #257

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