J Pole Antenna Design Calculator by K4ABT

J Pole Antenna Calculator by K4ABT
(http://www.hamuniverse.com/jpole.html).
Author:  G.E. "Buck" Rogers, Sr. (K4ABT).
Accessed on 25 April 2017, 04:55 hrs, UTC.
Please click link to read the full article.

Comment:

Thanks to G.E. "Buck" Rogers, Sr (K4ABT) for this ultra simple, easy to understand J Pole Antenna Calculator for HF, VHF, and UHF amateur radio bands.  Just enter the operating frequency and calculate the dimensions of your J Pole Antenna.  Using this type of antenna can be a bit tricky, so G.E. recommends the following additional step:

"On most of the J Pole designs out there, a choke should be used as close to the feedpoint of the antenna as possible to help prevent rf on the feedline and creating difficulty with SWR readings. For 2 meters, the coil is 4 turns of coax at 5 inches in diameter. You should get good results with the choke within 3 or 4 inches of the feedpoint on 2 meters.
Hint:
Use the last part of your feedline as the choke before attaching to the feedpoint!"

I've made a few J Pole antennas over the past few years, and they work great on the VHF and UHF bands.  J Pole antennas should give you about 3 dB gain over a monopole antenna.  One of these days, I'll make a J Pole antenna for 20 meters. That should be an interesting project.

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, strategic forecasting, politics, terrorism, and cybersecurity).

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)


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.