Saturday, May 18, 2019

Deploying an Off Center Fed Dipole Antenna for Ham Radio. Post 1871.


If you can't see the video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=D4P5DdvsLys.

In this video, we follow W5KV as he designs, assembles, erects, and uses an Off Center Fed Dipole for Ham Radio.  He discusses the materials, equipment, feed lines, and other tools necessary to make this popular HF antenna work efficiently.

For the latest Amateur/Ham Radio news and information, please visit these websites:

http://www.HawaiiARRL.info.
http://www.arrl.org.
http://www.arrl.org/arrl-audio-news (a weekly podcast which is updated each Friday afternoon).
https://oahuarrlnews.wordpress.com.
https://hamradiohawaii.wordpress.com.
https://bigislandarrlnews.com.
https://www.eham.net.
http://www.southgatearc.org.

Thanks for joining us today.

Aloha es 73 de Russ (KH6JRM).

Friday, May 17, 2019

80m END FED NVIS FIELD ANTENNA. Post 1870.


If you can't see the video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=jiaHtmOB57Y.

Your ARRL Field Day Antenna doesn't have to be complex and labor intensive.  In this video from NG9D, we see how a simple 80 meter end-fed NVIS antenna can bring hours of operating fun and reliable state and regional contacts. 

NG9D covers the basic theory and installation of the end-fed NVIS antenna, as well as demonstrating how easy it is to make contacts using simple equipment.

If you want to gather some local or regional contacts for your Field Day log, then try this simple, easily erected antenna.  With the use of balanced feed line and a wide-range "tuner", this NVIS antenna can cover several HF bands, giving you both daytime and evening capability with just one antenna.

For the latest Amateur/Ham Radio news and information, please visit these websites:

http://www.HawaiiARRL.info.
http://www.arrl.org.
http://www.arrl.org/arrl-audio-news (a weekly podcast which is updated each Friday afternoon).
https://oahuarrlnews.wordpress.com.
https://hamradiohawaii.wordpress.com.
https://bigislandarrlnews.com.
https://www.eham.net.
http://www.southgatearc.org.

Thanks for joining us today.

Aloha es 73 de Russ (KH6JRM).

Thursday, May 16, 2019

Random Wire antennas presentation. Post 1869.


If you can't see the video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=gUwBIG_8vTI.

Terry Snyder (WB3BKN) gave this excellent program at the 18 November 2018 meeting of the Harrisburg Radio Amateurs Club.  Terry covers a wide range of random wire issues, including lengths to avoid, grounding, radial systems, and feed line choices.  In addition to giving the lengths to avoid in random wire antennas, he provides a list of recommended wire lengths that should be easy to match with your antenna coupler (i.e. "tuner") and ground radial system.

Although Terry's presentation is well-done and easily understandable, I've found it simpler to follow two basic practices for random wire antennas.

If you're designing a wire antenna for a single band, make the wire 1/4 wavelength for your preferred frequency.  If you want 80 through 10 meter coverage, build an End Fed Half Wave (EFHW) antenna instead, using a 49:1 balun/antenna "tuner" combination coupled to a 1/2 wavelength antenna for your 80 meter frequency.  This antenna should cover amateur radio frequencies from 80 meters to 10 meters.

For the latest Amateur/Ham Radio news and information, please visit these websites:

http://www.HawaiiARRL.info.
http://www.arrl.org.
http://www.arrl.org/arrl-audio-news (a weekly podcast which is updated each Friday afternoon).
https://oahuarrlnews.wordpress.com.
https://hamradiohawaii.wordpress.com.
https://bigislandarrlnews.com.
https://www.eham.net.
http://www.southgatearc.org.

Thanks for joining us today.

Aloha es 73 de Russ (KH6JRM).


Wednesday, May 15, 2019

Ham Radio - Building a 4:1 balun. Post 1868.


If you can't see the video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=l5rLI8FpM9g.

If you're using a balanced feed line to energize your OCF (off-center fed) dipole, an EDZ (extended double zepp) antenna, or even a full-sized loop antenna, a 4:1 current balun is a necessary component to these popular HF antennas.  Used with an antenna transmatch (i.e. "tuner"), the easily-made 4:1 balun keeps excessive SWR in check, cuts back on RFI, and keeps common mode currents off your feed line.

In this video from Kevin Loughin (KB9RLW), we see how a couple of type 43 toroids, a common resistor, and some surplus wire pieces can be transformed into a useful, efficient 4:1 balun.  Kevin's explanations and demonstrations are clear, insightful, and easily understood. Make one of these baluns for your next HF antenna.

For the latest Amateur/Ham Radio news and information, please visit these websites:

http://www.HawaiiARRL.info.
http://www.arrl.org.
http://www.arrl.org/arrl-audio-news (a weekly podcast which is updated each Friday afternoon).
https://oahuarrlnews.wordpress.com.
https://hamradiohawaii.wordpress.com.
https://bigislandarrlnews.com.
https://www.eham.net.
http://www.southgatearc.org.

Thanks for joining us today.

Aloha es 73 de Russ (KH6JRM).

Tuesday, May 14, 2019

Ham Radio - A 40 meter folded dipole using window line. Post 1867.


If you can't see this video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=cS5nlutY_L4.

If you're looking for a HF antenna that shows some immunity to man-made noise, then the folded dipole may be worth trying. 

In this video, Kevin Loughin (KB9RLW) takes us step-by-step through the design, construction, and use of a 40 meter folded dipole antenna.  This antenna may prove beneficial in areas of high urban noise or other interference.

According to "Sparks" (W9DKB), "The folded dipole, being a loop, responds more to the magnetic (H) field of radio waves.  Most man-made noise is electrostatic (E) in nature and less (likely) to be picked up by magnetic antennas."

Your feedline can be TV ribbon line (300 ohms), ladder line (450 ohms), or even homebrew 600 ohm balanced line.  Be sure to use an antenna transmatch (i.e. "tuner") in conjunction with a 1:4 current balun to keep SWR and RFI to a minimum.

Kevin has done an excellent job of outlining the potential of an often ignored antenna design.

For the latest Amateur/Ham Radio news and information, please visit these websites:

http://www.HawaiiARRL.info.
http://www.arrl.org.
http://www.arrl.org/arrl-audio-news (a weekly podcast which is updated each Friday afternoon).
https://oahuarrlnews.wordpress.com.
https://hamradiohawaii.wordpress.com.
https://bigislandarrlnews.com.
https://www.eham.net.
http://www.southgatearc.org.

Thanks for joining us today.

Aloha es 73 de Russ (KH6JRM).