Search This Blog

23 April 2011

Vertical Antenna Research

I have not been on the air much since my last post in February 2011. During that time I've been researching vertical antenna theory and practice and have decided to see how much better I might be able to do switching from my homebrew dipoles to a quarter-wave vertical. There is a lot of good material to read. I've spent time reading Jerry Sevick articles and his book on short vertical antennas. I've also been downloading articles from the QST archives, a fabulous source of theory and practice. Lastly, Rudy Severns, N6LF, has a great web site on antennas which has been a huge source of information.

I have laid in a 180 degree network of 20, 25-foot radials buried about an inch or so in the soil on the back side of my house. I've ordered an S9v31 vertical. Although I have learned from my reading and study that there is likely to be signal loss using a 180 degree radial pattern (vs. a 360 degree radial pattern) there is not much I can do about that since I have almost no yard and there are restrictions on what I can put up in terms of antennas. My plan is to only put the antenna up at night when it cannot be seen. As it is, the antenna will be mounted on the back side of the house and will likely be all but invisible from the front of the house since the roof peak should hide just about all its length.

There has been a delay in receiving the S9 antenna because S9 was recently sold to LDG Electronics. S9 is selling the antenna through Cheap Ham who appears to be having difficulty shipping S9 orders.

I'm very excited to see what kind of improvement I may get using the vertical over my current dipoles which are literally wrapped around my house about 20 feet up, a height which greatly reduces their effectiveness and radiation angle. I hope that with the S9 vertical, I will get good low angle radiation and a reduction in losses in radiation since the antenna is not touching the house as the dipoles are. Plus, the vertical will be facing northwest primarily, which, combined with its low angle radiation, should theoretically skip signals over northern latitudes in a way my dipoles cannot currently.

I hope to report back in the next week or so.