Sunday, June 25, 2017

80 Meter Half Square. Post #1170.


If you can't watch this video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=2SBGdPMnH-E. You can also insert the post title into your browser search box to bring up the video.

If you spend much of your operating time contacting certain sections of the world, you may want to design and build a half square antenna for your favorite band.  I've used half square antennas for 20,15, and 10 meters with good results. At these frequencies, construction of this phased, bidirectional vertical antenna is fairly simple and can be aimed in the direction of your choice.  A theoretical gain of 3dB is possible, making the half square a worthwhile experiment.

In this post, Don Johnson (N4DJ) takes the half square a step further by building and using an 80 meter version of this antenna.  In the 80 meter band, this antenna can be quite large, often necessitating extra help in building and aiming the antenna in the preferred direction.  If you're willing to spend some time building this antenna, the rewards will pay off in a low radiation angle (around 15 degrees) and more contacts.  The half square antenna can be a valued part of your antenna "farm."

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.kh6jrm.info (Amateur Radio News & Information).
http://www.arrl.org
http://www.arrl.org/arrl-audio-news (weekly podcast issued each Friday).

Other sites of interest:

http://hawaiisciencedigest.com (science and technology news for radio amateurs).
https://hawaiiintelligencedigest.com (trends in geopolitical intelligence and cybersecurity).
https://paper.li/f-1482109921 (my daily intelligence briefing).

Be sure to check the blog sidebars for more antenna and propagation articles.

Opinions expressed in this blog are mine unless otherwise stated.

Thanks for joining us today.

Aloha es 73 de Russ (KH6JRM)

Saturday, June 24, 2017

Speaker Wire 44' Doublet Antenna. Post #1169


If you can't view this video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=e3x_uOzIFJ4.

Here's a simple, easy-to-build 40 through 10 meter HF Doublet Antenna made with commonly available parts.  In this video, Craig Sheppard uses 44-feet/13.414 meters of speaker wire, insulators made from milk bottle caps, a fiberglass crappie fishing pole, and a few hiking poles to make a lightweight portable HF antenna suitable for Field Days or any remote location.

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.kh6jrm.info (Amateur Radio News & Information).
http://www.arrl.org.
http://www.arrl.org/arrl-audio-news (this podcast is updated each Friday).

Other sites of interest:

http://hawaiisciencedigest.com (science and technology news for radio amateurs).
https://hawaiiintelligencedigest.com (trends in geopolitical intelligence and cybersecurity).
https://paper.li/f-1482109921 (my daily intelligence briefing).

Opinions expressed in this blog are mine unless otherwise stated.

Thanks for joining us today.

Aloha es 73 de Russ (KH6JRM)

Friday, June 23, 2017

Balloon Antenna Field Day 2016. Post #1168.


If you can't view this video, please enter this title URL into your browser search box: https://www.youtube.com/watch?v=GEDneotW3ko.

Here's an interesting, if somewhat complicated antenna worth trying for Field Days or any portable operation dedicated to the 160 meter Amateur Radio Band.
In this video from "HAMPREPPER.COM", we see how a few friends prepare a set of helium balloons to support a full 1/4 wavelength 160 meter antenna (around 135 feet/41.158 meters).  This project will take some coordination and excellent weather to make this antenna work.  With propagation favoring the 160, 80, and 40 meter bands this year, you may want to consider a balloon-supported antenna for Field Day, which happens on 24-25 June 2017.

For the latest Amateur Radio news and information, please visit these web sites:

http://www.HawaiiARRL.info.
https://oahuarrlnews.wordpress.com.
https://bigislandarrlnews.wordpress.com (becomes https://bigislandarrlnews.com on 25 June 2017).
http://www.kh6jrm.info (breaking news for radio amateurs).
http://www.arrl.org.
http://www.arrl.org/arrl-audio-news (podcast issued each Friday afternoon).

Other sites of interest:

http://hawaiisciencedigest.com (science and technology news for radio amateurs).
https://hawaiiintelligencedigest.com (trends in geopolitical intelligence and cybersecurity).
https://paper.li/f-1482109921 (My daily intelligence briefing).

Be sure to check the blog sidebars for more antenna and propagation articles.

Opinions expressed in this blog are mine unless otherwise stated.

Thanks for joining us today.

Aloha es 73 de Russ (KH6JRM)

Thursday, June 22, 2017

Antenna Deployment with Slingshot. Post #1167.


If you can't view this video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=XP9Arp7V9RA.

Thanks to Al (VE3RDD) and his fellow hams from the Bernie Amateur Radio Club for this refinement of an old antenna launching technique.  Al has paired a common slingshot with a fishing reel, fishing line, and a sinker to launch a Field Day antenna into nearby trees.  After a little practice, you'll be able to launch antennas into tree cover with few problems.  Be sure to participate in the 2017 ARRL Field Day Emergency Communications Exercise on 24 and 25 June 2017.
You don't have to belong to an amateur radio club to take part of the festivities. You can even run a portable ham station from your vehicle or from your own backyard.

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).
http://www.arrl.org.
http://www.arrl.org/arrl-audio-news (weekly podcast updated each Friday).

Other sites of interest:

http://hawaiisciencedigest.com (science and technology news for radio amateurs).
https://hawaiiintelligencedigest.com (trends in geopolitical intelligence and cybersecurity).
https://paper.li/f-1482109921 (My Daily Intelligence Briefing).

Be sure to check the blog sidebars for more antenna and propagation articles.

Opinions expressed in this blog are mine unless otherwise stated.

Thanks for joining us today.

Aloha es 73 de Russ (KH6JRM)

Wednesday, June 21, 2017

Random Wire Antennas. Post #1166.


Random Wire Antennas
(http://www.arrl.org/random-wires).
Accessed on 21 June 2017, 23:50 hrs, UTC.
Please click link or insert title into your browser to read the full article.

Comment:

Random wire antennas have been around since the dawn of Amateur Radio early in the 20th century.  Properly designed and attached to a suitable ground radial or counterpoise system, a random wire antenna will perform well and give you many contacts on Field Day or any other portable operation.

This article from the ARRL, gives you all the information you need to make a simple, inexpensive, and efficient random wire antenna.

The best length of a random wire antenna seems to be around 1/4 wavelength of your chosen band.  If you want to operate from 80 through 10 meters, make the wire length to accommodate the 80 meter band (around 135-feet/41.158 meters). For multiband HF use, an antenna "tuner" and a ground radial/counterpoise system are required.

According to the ARRL, a counterpoise or ground radial system supplies the "missing half" of your antenna and will do a lot to reduce RF in the shack:

"A counterpoise is simply a long, insulated wire that attaches to the ground connection on your antenna tuner. The best counterpoise is 1/4-wavelength at the lowest frequency you intend to use. That’s a lot of wire at, say, 3.5 MHz, but you can loop the wire around the room and hide it from view. The counterpoise acts as the other “terminal” of your antenna system, effectively balancing it from an electrical standpoint."

Good luck on Field Day--24 and 25 June 2017.

Aloha es 73 de Russ (KH6JRM).