Posts

2 Meter J-Pole Antenna Build. Post #1297.

Image
If you can't view this video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=cLqCtzqeQzI. If you want to get a bit more performance out of your 2 meter rig or handheld, try using a J-Pole antenna made from locally available parts.  In this video, Matt Heere used an online J-Pole calculator and some "upcycled" copper plumbing pipe to make this sturdy, effective 2 meter antenna. According to Matt, this omni-directional VHF antenna delivers a small amount of gain--around 2dBi--which may be enough to get full quieting on your favorite repeater.  Matt says he's able to contact a repeater almost 50 miles/81 km from his shack. For the latest Amateur Radio news and information, please visit these websites: http://www.HawaiiARRL.info. https://oahuarrlnews.wordpress.com. https://bigislandarrlnews.com. http://www.arrl.org. http://www.arrl.org/arrl-audio-news (a weekly podcast which is updated each Friday afternoon). https

Random Wire Antenna Lengths. Post #1296

Random Wire Antenna Lengths (https://udel.edu/~mm/ham/radio/randomWire/ Author:  University of Delaware. Accessed on 30 October 2017, 2055 UTC, Post #1296. Comment: When you're on the trail, at the annual Field Day, or wherever a good antenna is unavailable, a random wire antenna "can save the day" if  you know its limitations.  This article does an excellent job of describing the theory, construction, and use of random wire antennas and the wire lengths you should avoid if you want an efficient, effective operation without excessive SWR. Of particular note is the series of graphs showing various wire lengths to avoid for different sets of amateur radio bands. The basic guidance is clear:  "The fewer bands, the fewer high impedance regions to avoid." According to the article, you want the wire antenna to be at least 1/4 wavelength long for each band you want to use.  For example, to work the 40 meter amateur radio band (7 mHz), make sure the antenna

Building The MEF-1 Half-Wave End-Fed Antenna Tuner. Post #1295.

Image
If you can't view this video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=yRedmR9urE4. If you use end- fed or random length wire antennas, an antenna transmatch or "tuner" is necessary to gain maximum efficiency of the antenna while protecting your HF transceiver from excessive SWR.  In this video from Gil, the "Radio Prepper", we learn how to assemble the MEF-1 Half-Wave End-Fed Antenna Tuner kit from EA3GCY.  The tuner can be configured for any amateur radio band between 40 meter and 10 meters.  This tuner is strictly QRP, with the power limit set at 10 watts. For the latest Amateur Radio news and information, please visit these web sites: http://www.HawaiiARRL.info. https://oahuarrlnews.wordpress.com. https://bigislandarrlnews.com. http://www.arrl.org. http://www.arrl.org/arrl-audio-news (a weekly podcast which is updated each Friday afternoon). https://paper.li/kh6jrm/1430289353 (Amateur Radio New

An ATU aerial tuning unit for short wave HF end fed aerials. Post #1294.

Image
If you can't view this video, please insert this title URL into your browser search box: https://www.youtube.com/watch/v=o43sAF4HwJs. Ray of the "Radio Workshop" presents another outstanding video tutorial for radio amateurs.  In this video, Ray shows us how to design and build an "aerial tuning unit" for end fed wires, including inverted L antennas. The project is a simple, effective, and inexpensive L match ATU which can be used for both Amateur Radio and the international shortwave broadcast bands. Ray's easy going style makes often complex theory understandable and doable, even for those of us with limited construction skills. This easily-made L match ATU can be used for both home and portable operations. For the latest Amateur Radio news and information, please visit these websites: http://www.HawaiiARRL.info. https://oahuarrlnews.wordpress.com. https://bigislandarrlnews.com. http://www.arrl.org http://www.arrl.org/arrl-audio-news (a we

Buddistick Ham Antenna Camping Set Up. Post #1293.

Image
If you can't view this video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=v9m7XpgGkB4. Camping and Amateur Radio make a great combination.  You get a chance to get some physical exercise, enjoy the great outdoors, and operate free from urban noise and traffic.  A well organized campsite makes an excellent base of operations for portable operations.  In this video from Tinker John (W5CYF), we see how a simple, easily assembled antenna made from the popular Buddipole Antenna System can be used on a campsite ham station.  Buddipole antennas are well-built, high quality, and deliver outstanding performance in a small package. For the latest Amateur Radio news and information, please visit these websites: http://www.HawaiiARRL.info. https://oahuarrlnews.wordpress.com. https://bigislandarrlnews.com. http://www.arrl.org. http://www.arrl.org/arrl-audio-news (a weekly podcast which is updated each Friday afternoon). https://paper.

Tri-Band 20m 30m 40m Ground Plane Antenna. Post #1292.

Image
If you can't view this video, please insert this title URL into your browser search box: https://www.youtube.com/watch/v=hZ6i2wqa8vo. Here's an interesting three-band HF antenna you can build with commonly available materials and a little creativity. According to AB8XX, this ground plane antenna covers the 20, 30, and 40 meter amateur radio bands, is omnidirectional, and offers a low angle of radiation.  The feed point is approximately 20-ft./6.09-m above ground level.  Also intriguing in this article is the homebrewed antenna launcher based on a design published in the March 2009 issue of "QST."  The antenna spreaders are made from PVC pipe. For the latest Amateur Radio news and information, please visit these websites: http://www.HawaiiARRL.info. https://oahuarrlnews.wordpress.com. https://bigislandarrlnews.com. http://www.arrl.org. http://www.arrl.org/arrl-audio-news (a weekly podcast which is updated each Friday afternoon). https://paper.li/kh6jrm/

The K2MIJ 30 meter "Limbo Stick" antenna. Post #1291.

Image
If you can't view this video, please insert this title URL into your browser search box: https://www.youtube.com/watch?=Lcoh5JXZOA. Here's a strange, very shortened antenna that works well on the 30 meter amateur radio band (10.000 mHz to 10.150 mHz).  According to the author of this post, The 9-inch/22.86 cm vertical "halo" radiation section is made from AWG #10 wire and the loading coil uses 2-inches/5.08 cm of PVC pipe wrapped with AWG #26 to #14 wire.  The antenna displays a SWR below 2.0 for all frequencies in the 30 meter amateur radio band. Apparently, this experimental antenna works, although I suspect efficiency will be very low. For the latest Amateur Radio news and information, please visit these websites: http://www.HawaiiARRL.info. https://oahuarrlnews.wordpress.com. https://bigislandarrlnews.com. http://www.arrl.org. http://www.arrl.org/arrl-audio-news (a weekly podcast which is updated each Friday afternoon). https://paper.li/kh6jrm/143028