Saturday, December 31, 2016

Simple Ham Radio Antennas--The Double Bazooka Antenna - A Review


If you're having trouble viewing this video, please enter this URL into your browser search box: https://www.youtube.com/watch?v=9xfpcD6xuSo. This is post #998 in a continuing series on "Simple Ham Radio Antennas."

The Double Bazooka antenna is a worthwhile project whether you make one yourself or buy one from an Amateur Radio outlet. In this video, Bob (VK3BVW) reviews the popular double bazooka antenna made by IAC Antennas (http://www.iacantennas.com).

The antenna performed well on both 80 and 40 meters.  Bob does an excellent job of explaining the theory, design, and operation of this classic antenna.  If you can't build one yourself, contact IAC Antennas for more information.

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.
http://www.kh6jrm.info (breaking news for radio amateurs).
http://hawaiisciencedigest.com (latest science and technology news for radio amateurs).

Be sure to check out the blog sidebars for more antenna articles and the latest propagation forecasts.  These news feeds are updated daily.

Opinions expressed in this blog are mine unless otherwise stated.

Thanks for joining us today!  May your New Year be safe and sane.

Aloha es 73 de Russ (KH6JRM).


Friday, December 30, 2016

Simple Ham Radio Antennas--The WH2T mini short loop antenna. Post #997.

The WH2T mini short loop antenna
(http://www.iw5edi.com/ham-radio/?a-multi-band-super-mini-loop-antenna.160).
Author:  Simone (IW5EDI).
Accessed on 30 December 2016, 21:45 hrs, UTC.
Please click title link or enter the title URL into your browser searchbox.

Comment:

Loops are fascinating antennas.  They generally provide some gain over a dipole and exhibit low noise on receive. Loops can be used as multi-band HF antennas if they are designed and fed properly...almost sounds like child rearing.

In this post, Simone (IW5EDI) has designed what he calls "a super mini loop antenna" capable of covering all HF Amateur Radio bands between 80 meters and 10 meters, including the WARC bands.  Simone says the inspiration for this antenna comes from an inverted triangle loop designed by Dr. Ace (WH2T). A working copy of this loop was built and used successfully by Don (K8THU).

As with any loop antenna design, Simone says it's important to pay attention to details:

"This antenna works as a Full Wave Loop on 80 Meters and also works as a 2 wavelength open loop or Bi-Square on the 40 Meter band.
The gain is around 4 dBd on 40 mtrs, but it will seem much higher due to the very low angle, radiation pattern. Any antenna tuned for 80 Meters should also work on 20 and 10 meters as well. If an antenna works on 40 it should work on 15 as well. A tuner will probably be needed for 10, 18 and 24 MHz Band operations.

The loop is an inverted vertical triangle with the base along the top and what would be the apex hanging down. Or it could be erected horizontally if needed.

The feed point at the bottom uses a 3:1 or 4:1 balun and is then fed with any needed length of 50 ohm coax. The top center is broken with an insulator and has a 29 feet 10 inch length of 450 ohm ladder line connected across the insulator.
IMPORTANT - The 450 ohm ladder line is shorted across at the bottom end. "

If you want a HF multi-band, moderate gain, and quiet antenna, you may want to try this design from Simone (IW5EDI).

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

http://www.HawaiiARRL.info.
https://oahuarrlnews.wordpress.com.
https://bigislandarrlnews.wordpress.com.
http://www.kh6jrm.info (breaking news for radio amateurs).
http://hawaiisciencedigest.com (latest science and technology news for radio amateurs).

For additional antenna and propagation articles, please check out the blog sidebars. These news feeds are updated daily.

Opinions expressed in this blog are mine unless otherwise stated.

Thanks for joining us today!

Aloha es 73 de Russ (KH6JRM).



Thursday, December 29, 2016

Simple Ham Radio Antennas--Folded Dipole Calculator. Post #996.

Folded Dipole Calculator
(http://www.changpuak.ch/electronics/Dipole_folded.php).
(http://www.dxzone.com/dx32420/folded-dipole-calculator.html).
Accessed on 29 December 2016, 20:45 hrs, UTC.
Please insert title or title URLs into your browser search box to read the full article.

Comment:

Folded Dipole Antennas are an interesting variant on the familiar half-wavelength dipole design.  The folded dipole offers more bandwidth than a classic half-wavelength dipole and can be fed directly with 300 ohm television twin lead, since the nominal impedance of this antenna runs between 280 and 300 ohms.  I've made several antennas of this type, using 300 ohm television twin lead for both the antenna elements and the feed line.  You can match the folded dipole antenna to your rig with either a 1/4 wavelength coaxial cable transformer or though a balanced antenna transmatch (i.e. "tuner"). A 4:1 current balun/"tuner" combination works fairly well, too.

Use this handy tutorial to calculate the dimensions of your new Folded Dipole Antenna.  Measurements are in both foot and metric units.

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://hawaiisciencedigest.com (latest science and technology news).

Be sure to check out 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, December 28, 2016

Simple Ham Radio Antennas--Adding 80 metres to a 40 metre dipole


If you're having trouble viewing this video, please insert this title link into your browser search box: https://www.youtube.com/watch?v=4kXz6fPFKY. This is post #995 in a continuing series called "Simple Ham Radio Antennas."

Now that propagation is favoring the lower HF Amateur Radio Bands (160-40 meters), it may be a good idea to redesign your 40 meter dipole antenna to accommodate the 80 meter (3.5 MHz) band.  If you live on a small urban lot, extending your 40 meter (7 MHz) dipole antenna may present some challenges.

In this video from Peter Parker (VK3YE), we learn how to use a 7 MHz dipole antenna on 3.5 MHz by adding end-loading coils.  Although this modification won't be as effective as a full-length 80 meter dipole and will be a bit narrower in bandwidth, it will get you on the air.  You may also use the 40 meter part of this modified antenna to work stations on the 15 meter (21 MHz) band, since the 40 meter elements will be usable as a 3/2 dipole on 15 meters.  An antenna transmatch (i.e. "tuner") will be helpful in keeping SWR to a low level.

For the latest Amateur Radio news and information, please check out these websites:

http://www.HawaiiARRL.info.
https://oahuarrlnews.wordpress.com.
https://bigislandarrlnews.wordpress.com.
http://www.kh6jrm.info (breaking news for radio amateurs).
http://hawaiisciencedigest.com (latest news from science and technology).

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).

Tuesday, December 27, 2016

Simple Ham Radio Antennas--Bobtail Curtain Antenna


If you can't view the video, please insert this title link into your browser search box: https://www.youtube.com/watch?v=6dU2b0AHD1M. This is post #994 in a continuing series on Simple Ham Radio Antennas.

The Bobtail Curtain Antenna is one of those projects that will take some time and effort to do correctly.  You may want to ask some of your ham radio friends to help you design, build, and erect this effective bidirectional, monoband, broadsided wire antenna for the HF Amateur Radio bands.

Stan Gibilisco (W1GV) does a good job of explaining the theory, design, and use of this unusual antenna.  I used one of these antennas a few years ago during an ARRL Field Day event on Hawaii Island.  The 20 meter version of this antenna did an excellent job in capturing elusive Pacific Island contacts. In years gone by, many international shortwave stations used curtain arrays to direct their signals around the world.  If you want a different kind of antenna project, try the bobtail curtain array.  It's worth the time and 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).
http://hawaiisciencedigest.com (latest science and technology news).

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

Opinions expressed in this blog are mine unless otherwise stated.

Thanks for joining us today!

Aloha es 73 de Russ (KH6JRM).

Monday, December 26, 2016

Simple Ham Radio Antennas--Center Connector for Dipole Antenna. Post #993

Center Connector for Dipole Antenna
(http://www.k4icy.com/dipoleconnector.htm).
Accessed on 26 December 2016, 19:30 hrs, UTC.
Author:  Michael A. Maynard (K4ICY).
Please click title or insert title URL into your browser search box.

Comment:

Often times, the weakest part of your dipole antenna is the center connector. Depending on the materials used for the center support, the connector may be subject to extreme stress from holding up the weight of your long HF dipole and from the accumulated effects of severe weather.

Although you can buy commercial versions of center connectors, it may be cheaper and more instructive to "roll your own."

In this well-written article from Michael A. Maynard (K4ICY), we learn a simple, nearly foolproof method of making a center dipole connector that will survive  severe weather and support the weight of your full length dipole antenna. Although Michael calls the project "advanced", a little patience and attention to detail will reward you with a sturdy center connector capable of supporting any dipole antenna you erect. And best of all, you have the pride of building something useful without spending a lot of money.

Michael takes you step-by-step through the assembly process and illustrates his text with helpful photographs.  Parts for the project are simple, inexpensive, and available at the nearest hardware store or building supply outlet.  Good luck!

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For the latest Amateur Radio news and information, please check out these websites:

http://www.HawaiiARRL.info.
https://oahuarrlnews.wordpress.com.
https://bigislandarrlnews.wordpress.com.
http://www.kh6jrm.info (breaking news for radio amateurs).
http://hawaiisciencedigest.com (latest science and technology news).

Be sure to check out the blog sidebars for more antenna and propagation articles. These news feeds are updated daily.

Opinions expressed in this blog are mine unless otherwise stated.

Thanks for joining us today!

Aloha es 73 de Russ (KH6JRM).

Sunday, December 25, 2016

Simple Ham Radio Antennas--Inverted "U" Antenna


If you're having difficulty viewing this video, please insert this title link into your browser search box: https://www.youtube.com/watch?v=Q2UlV5V7Em4. This is post #992 in a continuing series of Simple Ham Radio Antennas. Here's another fascinating idea for those radio amateurs wanting to experiment with unusual, but effective HF antennas.  In this video, Stan Gibilisco (W1GV) explains the theory, design, construction, and use of the "Inverted U Antenna".  This antenna is particularly useful in portable or emergency operations.  The antenna is easy to build, inexpensive, and readily deployable.

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://hawaiisciencedigest.com (latest science and technology news).

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

Opinions expressed in this blog are mine unless otherwise stated.

Thanks for joining us today! Happy Holidays to all!

Aloha es 73 de Russ (KH6JRM).