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Showing posts with the label Antenna tuner

Simple Ham Radio Antennas--A Simple Wire Antenna Tuner. Post #325.

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If you're looking for a basic, simple antenna transmatch ("tuner") for that "long wire" or random length wire connecting your transceiver to the "ether", you've found the right place. Stan Gibilisco (W1CV) provides an easy to understand tutorial on how to build a random wire antenna "tuner" for your QTH or for that portable operation on the weekends. The "tuner" can also work with end-fed half-wave antennas. It's important to have a good ground or radial system with this type of antenna. I built a similar antenna transmatch during my Novice License years (1977-1979) and got a lot of enjoyment and contacts with it. As I recall, I was using a Heathkit HW-101 transceiver attached to a 100-ft/30.48 meters wire strung up in a tall Norfolk Pine Tree. My radial system consisted of an 8-ft/2.43 meters copper ground rod with four, 33-ft/10.06 meters radial wires attached and buried about 1 inch/2.54 cm below the lawn. My feed

Simple Ham Radio Antennas: M0VST's 50 meter longwire antenna set up. Post #307.

This short video by M0VST covers most of the basics involved in making an effective longwire antenna, covering the amateur radio bands between 160 to 10 meters . I've built several of these "longwire" antennas and have found that an ATU ( antenna tuner ) and a good counterpoise system really help to produce a quality signal. Unlike M0VST's "longwire antenna", my version was cut to a length of 67-ft/20.42 meters, enough to cover amateur radio bands between 80 and 10 meters. My counterpoise system was a compromise arrangement consisting of four, quarter wave radial wires for each band of use (80, 40, 20, 15, and 10 meters). I also attached a "quarter wave radial bundle" to the ground lug of my trusty Drake MN-4 ATU. I used approximately 60 ft/18.29 meters of 450 ohm ladder line as the antenna feed line. The ladder line was attached to a W9INN 4:1 balun. A 6-ft/1.82 meters length of RG-8X with UHF connectors ran from the balun to the wi

Simple Ham Radio Antennas. The Open-Wire Dipole (Doublet). Post #293

I'm still in the process of restoring my "antenna farm" after the passing of Tropical Storm Iselle on 07-08 August 2014.  I lost a few trees on my Orchidland Estates property, most of which were supporting several HF wire antennas.  I salvaged most of the wire and the 450 ohm feedline from the storm.  While I cleaned up the mess, I erected a simple multiband vertical antenna using a tall Norfolk Pine Tree as an antenna support. Next on the list is the restoration of my approximately 134-ft/40.85 meters  center-fed horizontal dipole.  The antenna is fed with 450 ohm ladder line which goes into a W9INN 4:1 balun and then via a short length of RG-8X coax into a MFJ 941E Versa Tuner II.  This feed arrangement allows multiband coverage from 3.500 MHz through 29.000 MHz. Although the antenna requires two tall supports (trees or masts), construction of the antenna is simple and the dipole doesn't require a ground radial system. Using the general formula, 468/f(

Simple Ham Radio Antennas. A 5-band vertical dipole. Post #286

How would you like to have a 5-band vertical antenna that covers 20, 17, 15, 12, and 10 meters that requires no ground radial system and can be built from materials from your junk box or from the nearest hardware store? You can, if you build a simple Vertical Dipole and feed it with 300 ohm television twin lead or 450 ohm ladder line terminated into a balanced antenna "tuner." If your "tuner" has no provision for balanced feeders, you can insert the twin lead/ladder lead into a 4:1 current balun and use a short piece of 50 ohm coaxial cable to connect the antenna to your "tuner." I got this idea from an article in "Simple and Fun Antennas for Hams" by Chuck Hutchinson (K8CH) and Dean Straw (N6BV).  Hutchinson and Straw conducted a series of antenna experiments using 15 meter vertical dipoles in a space-restricted urban area. The results of their work were impressive, so I decided to use some of their suggestions and make my own version of

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 ground plane. Post #272

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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

Simple Ham Antennas: The Novice 40 meter delta loop. Post #271

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During that brief period between getting my novice amateur radio license and moving on to the technician and general class license (1977-1983), I built several dipoles, inverted vees, and verticals.  All of these antennas worked very well, considering the lack of space I had at the time.  When my xyl and I moved from Honokaa to Laupahoehoe , we occupied a larger home and had more backyard space to place antennas. Just before I passed the Advanced Amateur License exam, I built what I considered my best and "most forgiving" antenna--a full-wavelength 40-meter loop.  The loop displayed some gain over a dipole at the same height, needed only one tall support, and didn't require a ground radial system to operate efficiently.  Using balanced feed line , a 4:1 current balun, and a Drake MN-4 transmatch, I could cover 40, 20, 15, and 10 meters with one antenna.  Later on, when 30 meters became available to amateur radio operators, I used a MFJ-941-E Versa Tuner II and my sp

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

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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: An 80-10 meter inverted vee dipole. Post #263

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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

Simple Ham Radio Antennas: The 10 meter 1/2 wavelength sloper. Post #262

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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

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

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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 Radio Antennas: A Low HF Band Triangle. Post #259

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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