Posts

End-Fed Wire Antennas. Post #1117.

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If you can't view this video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=264KI-xyxXE. End-fed random wire antennas can sometimes be the solution to erecting HF antennas on small urban or rural lots.  In this video, Stan Gibilisco (W1GV) discusses the advantages and disadvantages of these simple, easily made antennas.  As with any compromise antenna, there are significant problems related to SWR, antenna matching, and grounding systems.  Stan does a good job of explaining how to overcome the design limitations of end-fed wires.  To use one of these antennas, particularly wires ranging from 30 feet/9.146 meters to 40 feet/12.195 meters, you'll need a wide-range antenna transmatch (i.e. "tuner") and a good ground radial or counterpoise system.  The use of balanced feed line, such as 300 ohm television twin lead or 450 ohm ladder line, in conjunction with a 4:1 current balun and an antenna "tuner", will enable

kf4bwg ham horse fence antennas. Post #1116.

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If you can't view this video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=OdIFgaR1Fig. Never underestimate the creativity of amateur radio operators.  In this video, we see how KF4BWG uses horse fence wire to make and operate a multiband HF dipole antenna.  If you have a metal fence on your property, consider using it for either the antenna or part of a ground radial system. You may be surprised how well this "antenna of convenience" works. For more Amateur Radio news and information, please visit these websites: http://www.HawaiiARRL.info. https://oahuarrlnews.wordpress.com. https://bigislandarrlnews.wordpress.com. http://www.kh6jrm.info (breaking news for radio amateurs). Other sites of interest: http://hawaiisciencedigest.com (science and technology news for radio amateurs). https://hawaiiintelligencedigest.com (trends in geopolitical intelligence, strategic forecasting, terrorism, politics, and cybersecur

Antenna Gain. Post #1115.

Antenna Gain (http://www.eham.net/articles/38645). Author:  Robin Cross (W0FEN). Accessed on 29 April 2017, 04:55 hrs, UTC. Please click link to read the full article. Comment: A simple, excellently phrased tutorial on Antenna Gain/Antenna Directionality for VHF/UHF by broadcast engineer Robin Cross (W0FEN). Robin discusses the pros and cons of having "gain" antennas for VHF/UHF mobile work.  Robin says there are times when a simple 1/4 wavelength whip will produce more contacts than the 5/8 wavelength "gain" antennas being touted in the media.  He cites several examples where a shorter antenna will often prove more satisfactory than a higher gain mobile antenna. Robin says you can use a simple test to determine if a "gain" antenna is necessary for your mobile operation: To visualize this, hold your hand out with the first two fingers in a V shape. Your fingers should be above and below horizontal. As you rotate your hand vertically, the li

A Simple Short Vertical HF Antenna.. Post #1114.

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If you can't view this video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=8_Axs2ut7sE. Thanks to Gil (aka RadioPrepper.com) for this simple, effective vertical antenna which can be used for both home and portable operations.  The 19 foot/5.79 meters antenna wire is supported by a 19.68 foot/6 meter telescoping fiberglass fishing pole.  The antenna system uses a small Z-Match antenna "tuner" and a 9:1 EARCHI UNUN along with a suitable ground radial system.  Gil's rig is an Elecraft KX2 running about 5 watts output.  In the video, he's enjoying a cw contact with a station in Sweden.  Gil's entire system (rig, antenna, tools, and power supply) is contained in a small carrying case which can be stuffed in a knapsack or kept in a vehicle for emergencies.  A very nice arrangement. For the latest Amateur Radio news and information, please visit these websites: http://www.HawaiiARRL.info. https://oahuarrlnews.wo

My Vertical Loop Antenna for 80 Meters. Post #1113.

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If you can't view this video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=o1SePX-NPrw. With propagation now favoring the lower HF bands (160 meters through 40 meters), you may want to make a simple, effective antenna for the 80 meter band which will deliver good daytime regional performance as well as some good night time contacts. In this video, "Lockemeister" shows us one of his experimental vertical loops for 80 meters.  You can get acceptable 80 meter performance with a 50 ohm coaxial cable feed line and an antenna transmatch (i.e. "tuner").  To cut down on RF feedback and SWR losses, you may want to attach a 4:1 balun to the feed line just before it enters your "tuner".  Another suggestion would be to feed the antenna with 300 ohm television twin lead or 450 ohm ladder line connected to a 4:1 balun before it runs into your "tuner".  This will give your loop antenna multiband capabilit

10 Ultra Stealth Antenna Designs for HOAs. Post #1112.

10 Ultra Stealth Antenna Designs for HOAs (http://forums.qrz.com/index.php?threads/10-ultra-stealth-antenna-designs-for-hoas.260566/). Author:  KC8VWM. Accessed on 26 April 2017, 05:35 hrs, UTC. Please click link to read the full article. Comment: Operating from a deed-restricted property can be challenging.  Just because the "housing police" says "no antennas" doesn't mean you can't get on the air.  You have to be clever and "stealthy" to erect an antenna where restrictive rules are the order of the day. In this article by KC8VWM, we learn how common, everyday objects such as old satellite dishes, bicycles, and even a badminton net can be used as makeshift antennas without your neighbors even knowing about your real intentions. Here are 10 ideas for making an "ultra stealth antenna" in deed-restricted housing: Use a Weather Instrument project as an antenna. Solar powered lights can be used for informal vertical antennas,

J Pole Antenna Design Calculator by K4ABT

J Pole Antenna Calculator by K4ABT (http://www.hamuniverse.com/jpole.html). Author:  G.E. "Buck" Rogers, Sr. (K4ABT). Accessed on 25 April 2017, 04:55 hrs, UTC. Please click link to read the full article. Comment: Thanks to G.E. "Buck" Rogers, Sr (K4ABT) for this ultra simple, easy to understand J Pole Antenna Calculator for HF, VHF, and UHF amateur radio bands.  Just enter the operating frequency and calculate the dimensions of your J Pole Antenna.  Using this type of antenna can be a bit tricky, so G.E. recommends the following additional step: "On most of the J Pole designs out there, a choke should be used as close to the feedpoint of the antenna as possible to help prevent rf on the feedline and creating difficulty with SWR readings. For 2 meters, the coil is 4 turns of coax at 5 inches in diameter. You should get good results with the choke within 3 or 4 inches of the feedpoint on 2 meters. Hint: Use the last part of your feedline as the cho