Posts

Adding 80 metres to a 40 metre dipole. Post #1110.

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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=4kXRz6fPFKY. If you live on a small urban or rural lot, erecting a full-size 80 meter horizontal dipole antenna can be quite a task.  In this video from Peter Parker (VK3YE), we learn how to convert a 40 meter horizontal dipole antenna into a serviceable dipole for the 80 meter band.  The secret is to add loading coils to both ends of the dipole antenna.  Peter supplies the necessary coil winding data, materials list, and tuning procedures to get your old 40 meter dipole working on the 80 meter band.  Although this modification won't be as efficient as or capable of the same bandwidth of an 80 meter dipole, this antenna will get you on the air from a small size lot.  You may even be able to operate this antenna on the 3rd harmonic of 15 meters, where the 40 meter portion of the dipole will serve as a 3/2 wave length antenna on 15 meters. For the latest

Antenna Loading with Coils. Post #1109.

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If you can't view this video, please insert this title URL into your browser search box: https://wwww.youtube.com/watch?v=XjtE_SZjQ-g. In this video from Stan Gibilisco (W1GV), we learn the a classic way to shorten a dipole antenna without sacrificing performance and ease of operation.  If the coils are built correctly, you will lose only a small percentage of the signal normally found on a full horizontal  half wave dipole antenna.  Stan does a good job of explaining the theory, design, and operation of this easily made HF antenna.  This antenna is a good compromise for radio amateurs living on a small city or rural lot. For the latest 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).

Homemade 70cm Yagi Beam Antennas. Post #1108.

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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=1WI6Cy4ovig. Here are two excellent examples of 70 cm Yagi beam antennas made from commonly available materials.  The first antenna is a 7-element beam with a wooden support structure, while the more polished 10-element beam uses aluminum to support the antenna elements.  Both antennas, along with a sturdy rotator atop a small mast, will give you excellent performance between 430-440 MHz (70 cm).  You can cut the antenna elements to conform to the 70 cm allocations in your area.  Video supplied by M0UKD). For the latest 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)

Six Element Collinear Antenna. Post #1107.

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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-T5OMkha4k_4. Why should repeaters have all the fun when it comes to antennas?  In this video, Stan Gibilisco (W1GV) shows us how to make a six element VHF collinear antenna that will give your signal a significant boost.  Stan bases his antenna on a popular collinear design used for VHF repeater sites.  Although the project takes a bit of work and experimentation, the improved results on the 2 meter band will be worth the effort. For the latest 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,

The 25-Foot Untuned Vertical--7 Bands. Post #1106.

The 26-Foot Untuned Vertical--7 Bands (http://www.eham.net/articles/29052). Author:  Dave Benzel (KD6RF) Accessed on  20 April 2016, 02:50 hrs, UTC. Please click link or insert title URL into your browser search box to read the full article. Comment: If you want a fairly efficient, multiband HF vertical that is only 25 feet/7.62 meters long, then this untuned vertical from Dave Benzel (KD6RF) is just what you need.  According to Dave, the 25 foot/7.62 meters long antenna is "quantitatively similar" to the 43 foot/13.109 meters vertical antenna, but is only about half as long and "is designed to provide acceptably efficient operation from 40 through 10 meters."  With ground and feedline losses major issues for vertical antennas, Dave solved those issues by using 7/8" heliax feedline, an elevated counterpoise consisting of a long metal fence, and nearby "shorting rod" with a coil, which serves as a decoupling device for higher bands. Dave pro

Building a dipole for 40 and 20 meters. Post #1105.

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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=RVKRnQmrx3k. Here's an easily made dipole antenna for 40 and 20 meters that could be used for portable, home, or emergency operations.  This antenna can serve as a backup antenna for the 2017 ARRL Field Day Event, set for 24-25 June 2017. If you follow the step-by-step instructions from "RC286", you should have a working 40/20 meter dipole antenna in a few hours. Most of the materials can be found at the nearest hardware store or building supply outlet. For the latest Amateur Radio news and information, please visit these websites: http://www.HawaiiARRL.info. https://oahuarrlnews.wordpres.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.co

Tuning the 40/80 Meter Inverted V Dipole Antenna. Post #1104.

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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=IKuLDnwuy8M. Here's another great antenna idea for the upcoming 2017 ARRL Field Day Event on 24-25 June 2017.  With propagation favoring the lower HF Amateur Radio bands (160 meters through 40 meters), a combination 40/80 meter coil loaded inverted V dipole would make an ideal antenna for this annual event.  With the proper coils, an antenna "tuner" won't be necessary to work 40 and 80 meters, which should give regional daytime performance and good night time range. An inverted V only needs one supporting mast and a few tie-off stakes. Dave Tadlock (KG0ZZ) does an excellent job of explaining how to tune this two-band antenna.  When you're done with Field Day, keep this project in your shack in the event of emergencies or local DX-peditions. Also, Dave has produced an outstanding video explaining how to build this antenna.  To see t