Skip to main content

Comparing the performance of an inverted vee dipole with a small transmitting loop on 40m. Post. #1126.

Comparing the performance of an inverted vee dipole with a small transmitting loop on 40m
(http://www.sotabeams.co.uk/blog/comparing-the-performance-of-an-inverted-vee-dipole-with-a-small-transmitting-loop-on-40m/).
Accessed on 09 May 2017, 19:15 hrs, UTC.
Author:  Richard Newstead.
Please click link to read the full article.

Comment:

Have you ever questioned the efficiency and ease of operation of the antenna you use for portable operations, such as SOTA, IOTA, and Field Day activities? Radio amateurs certainly have a wide selection of antennas available for such activities, ranging from homemade dipoles to commercially made verticals and magnetic loops.

In this expertly written essay, Richard Newstead compares two popular antenna systems:  an inverted vee dipole and a small transmitting loop called the "Chameleon P-Loop."

In "carefully controlled conditions", Richard puts each antenna through a series of transmitter tests, reception reports, and performance parameters to determine the efficiency and effectiveness of each antenna.  He supplies graphs, photos, and other data to underline his methodology.

While both antennas performed well with WSPRite low powered transmitters (about 200 mW output), the inverted vee dipole proved to be the more efficient antenna during these tests.

Here are Richard's conclusions:


The antenna configurations tested are typical of a SOTA deployment, and the experimental results suggest that the Inverted V antenna is about 15 dB better performance than the P-Loop antenna as tested.

NEC models suggest that the radiation efficiency of the Inverted V is around 42% or -3.8dB, and the P-Loop would appear to be about 15dB lower at -18.8dB or 1.3%.

No practical HF antenna is 100% efficient, the important outcome of this experiment is that you can expect the Inverted V to be around 15dB better than the P-Loop in similar situations.
The loop efficiency will improve on higher frequencies.
Addendum: 
1. The manufacturer of the P-loop gives a calculated efficiency of 5.674% at 7150 kHz. The calculation method is not shown.
2. The comparison above has not been normalized to account for the small differences in feeder losses as it was designed primarily to be a system-level comparison for typical portable configurations.

With thanks for helpful suggestions from Owen Duffy (9-May-17)

-------------------------------------------------------------

Aloha es 73 de Russ (KH6JRM)

Comments

Popular posts from this blog

G5RV Multi Band HF Dipole Antenna. Post #1555.

If you can't see the video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=aeNHIQ_j4Dk

This well-produced and richly illustrated tutorial on the classic G5RV HF Dipole Antenna was presented to the Brandon Amateur Radio Society in Brandon, Florida in 2017 by Bernie Huth (W4BGH).  Bernie does an excellent job of  explaining the pros and cons of this popular HF antenna from the late Louis Varney (G5RV).  Although Varney envisioned his design primarily as a 3/2 wavelength antenna for the 20 meter Amateur Radio band, radio amateurs have used the antenna for multiband use.  The G5RV is an excellent choice for the 20 meter band.  Performance on other HF Amateur Radio bands is good enough to qualify as stand alone HF antenna if you can only erect one 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 podca…

Amateur Radio Bicycle Mobile Setup. Post #1554.

If you can't see the video, please insert this title URL into your browser search box: https://www.youtube.com/watch?v=2zWb-KnkGdY.

Here's a way to use Amatuer/Ham Radio while you work on shedding a few pounds in useful exercise.  Why not equip your bicycle for 2 meter/70 cm mobile operation?

In this short, well-made video, "taverned" shows us how he used a mag mount antenna, a simple C clamp, and a basic ground system to convert his mountain bike into a mobile station.  The project is straight forward, simple, and gives you emergency communications while you peddle down the road.

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://hamradiohawaii.wordpress.com.
https://bigislandarrlnews.com.
https://amateurradionewsinformation.com (Amateur Radio News & Information).
https://www.eha…

An 80-Meter Vertical Helix

Like many amateur radio operators, I live on a small lot surrounded by neighbors, utility lines, and civic-minded citizens concerned about the "attractiveness" of my community.  Whether by design or outright fear, I've adopted the "stealth" approach to ham radio antennas.  It's the old "out of sight, out of mind" idea applied to amateur radio antennas.

The amateur radio press is full of articles describing the struggle of amateur radio operators to pursue their hobby under the burdensome regulations of CC & Rs, HOAs, and other civic minded citizens who object to antenna farms.  So far, my modest verticals, loops, and inverted vees have blended well with the vegetation and trees bordering my small backyard.  Vertical antennas have always been a problem because of the limited space for a radial system.  There are times, however, where a shortened vertical for the lower HF bands (such as 80/75 meters) is necessary where horizontal space is lacki…