5/8 Wave Vertical Antenna Calculator. Post #1029.

5/8 Wave Vertical Antenna Calculator
(http://www.qsl.net/w4sat/five8th.htm).
Accessed on 01 February 2017, 04:50 hrs, UTC.
Author:  W4SAT.
Please click link or insert title URL into your browser search box to read the full article.

Comment:

You can design, build, and operate your own 5.8 wavelength vertical antenna by using this simple javascript antenna calculator. An antenna matching device, such a wire-wound coil, must be added between the vertical antenna element and the coaxial cable feedline so that the antenna can match the impedance of the coax feedline.  The addition of 3 to 4 quarter wavelength radials will make the antenna more efficient and easier to adjust.

As you can guess, the 5/8 wave antenna is a bit more complex to build than the simple ground plane antenna using a 1/4 wavelength vertical element.  So, why go to all the trouble of building the 5/8 wavelength vertical antenna?  W4SAT gives us several reasons to build this larger vertical antenna:

"So why would anyone use a 5/8 wave antenna if they have to go through all that extra work? After all, a ground plane antenna provides a nicer match. There are a couple of answers. The first is GAIN. The computer shows that the antenna (mounted 1 foot above ground) has a gain of about 1.5 dBd higher than a dipole's gain (also mounted 1 foot above ground.) 

The second reason you may want to use the 5/8 wave vertical is to obtain a lower angle of radiation. A half wave antenna's radiation peak angle is 20 degrees. You'll find that the 5/8 wave antenna's angle of radiation is just 16 degrees making it an even better dx antenna."

Supportable 5/8 wavelength wire antennas can be built for any amateur radio band, but using this antenna on bands between 20 meters and 70 cm seems to be the most practical from a standpoint of space and materials.

In this post, an experimental 5/8 wavelength wire antenna was built using a chosen frequency of 28.5 MHz, with the vertical element measuring 22.5 feet/6.85 meters.

To use the 5/8 wavelength formula, just plug in your chosen frequency and select meters or feet as your preferred measurement.  The formula is based on the common expression of 585/f (feet)/178.307/f (meters)=length.

----------------------------------------------------
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).

Other sites of interest:

http://hawaiisciencedigest.com (latest science and technology news for radio amateurs.).
https://hawaiiintelligencedigest.com (trends in geopolitical intelligence, strategic forecasting, terrorism, and cybersecurity).

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)

Comments

Popular posts from this blog

Antenna for Condo Backyard-Stealth. Post #1542.

G5RV Multi Band HF Dipole Antenna. Post #1555.

Amateur Radio Bicycle Mobile Setup. Post #1554.