Showing posts with label radials. Show all posts
Showing posts with label radials. Show all posts

Wednesday, September 09, 2009

Hygain Vertical Performance

The Hygain Vertical I purchased has been working well. I hope to run it thru more on-the-air tests over the next few weeks. But during the ARRL /140 contest, it performed well and I made contacts on 10M, 20M, and 40M with it. I have learned a lot about short vertical antennas and I hope to try some other things with it.

For a quick review, the antenna is the Hygain 18VS model. Total cost is $100. It is 18 feet tall and has a loading coil at the base. This is just about as simple as an antenna gets.


I have mine put in an umbrella stand so I can move it to the patio when we mow the lawn. I have a number of radials (minimum of 4) that I attach to the base of the antenna and one ground wire from the antenna base to a 12 inch stake driven into the ground.

This week, I have 10 radials attached to the antenna. Four of the radials are 17 feet and 6 are 13 feet. They are just laid on the grass.

The loading coil tap can be set to make the antenna resonant on just about any frequency from 10M to 80M. I set the tap so the antenna is resonant on 10M. So when I switch to 10M, I do not need my antenna tuner. When I am on 20M, 30M, or 40M I have to use my antenna tuner to get the SWR down under 2.

One of the ideas I have been thinking about is purchasing an antenna tuner to fit at the base of the antenna. These are a little pricy at about $260. That would make the antenna an all-band for sure. But, if I did that, the total cost of the antenna and tuner would be about what a screwdriver-type antenna would cost.

So, the addition of an automatic tuner and more radials are in the plans. I will install the antenna permanently after mowing season is gone. I'll drive a post in the ground to mount the antenna on. I think this will give a much better ground and perhaps improve the way the radials work. The antenna will really be ground mounted instead of 10 inches off the ground.

...AR

Wednesday, August 05, 2009

1010 Summer Phone Contest (Aug 1,2)

The 1010 Organization held their Summer Phone contest this past weekend. It gave me a chance to check out my "small vertical" and I was pleased with the antenna over all. I ended with 31 QSOs and 14 states distributed across the U.S.

My antenna is a Hygain 18 foot vertical with a loading coil at the base. It is ground mounted with 4 radials of 13 feet each and one ground rod. The loading coil is not needed on 20 meters, but I did have to use a couple of turns for 10 meters.
I was able to work just about everyone I could hear.

On Saturday, contacts were few and far between. I only made about 5 the whole day. Sunday, however, things opened up and I made the rest of the contacts from about 10 a.m. until 3 p.m. IF I had started earlier, I'm sure I could have doubled my count.

Anyway, it was fun. Click here for the 1010 website.

...AR

Sunday, July 12, 2009

Vertical Antenna Ground System

When I come across really useful information, I just have to pass it along. Rudy Severns, N6LF, did an incredible amount of work during the spring of 2008 to evaluate the effect of radials on the effectiveness of 1/4 wave vertical antennas.

For the whole set of articles, click here:


In his Vertical Antenna Ground System Experiment No. 4, he makes the following observations:

1. If you are limited to 4 radials for whatever reason, you can SHORTEN the radials (from a 1/4 wave) by up to 40 percent and improve your gain by 2.9 dB. Or you can add a ground rod (4 ft.) and improve your signal gain by almost 3 dB. But doing both does not seem to improve things any more than doing either one. I know, read it for yourself.

2. If at all possible, use at least 8 radials. With the 8 radials you improve your signal gain by about 2.5 dB over the 4 radials and the gain can be improved to 3.9 dB by shortening your radials by about 40%.

3. If you can get to 16 radials, then you have overcome most of the ground losses and shortening the radials is no longer a major factor. He says, "I would think that with 32 or more radials, you wouldn't worry about resonances in the radial screen. The problem is only important when fewer than 16 radials are deployed over average or better soil."

There is a lot more information at his web site and I have not made it through all of it yet. Very good stuff!

... AR