Radio operators typically want to get the best performance and range out of their antenna systems. VHF and UHF  propagation is typically line of site, so the common thought to increasing range is to increase the antenna height. For the most part this works, but when you look at the numbers, you will notice an decreasing rate of return for each foot that you increase in your antenna’s height.

To calculate range for an antenna such as the KB9VBR J-Pole antenna, you can use this simple equation to determine antenna’s receiving range over a flat surface: range in miles = square root of height X 1.42. An antenna mounted at 30 feet should have a theoretical range of 7.78 miles. Of course terrain and surrounding buildings and landscape can greatly affect this number.

You’ll notice that doubling the antenna height doesn’t automatically double the range. If you wanted to double the range, you’ll need to triple the height. In order to get greater and greater return in antenna distance, we need to increase the antenna height quite an appreciable amount.

It’s also worth noting that terrain makes a big difference in communications. These numbers are for a flat surface or over water. If you live in a valley or on a hilltop, you’ll find that your range will vary greatly. There are more sophisticated calculations that you can make to figure your antenna’s height above average terrain, and how high you’ll need to be to effectively communicate based on terrain. Increasing your transmitter’s power can also affect the range, using a 50 watt transmitter vs a 5 watt transmitter can affect distance greatly.

But this formula should give you a great ballpark estimate of the range or distance your antenna will experience.

As I write this, we are in the midst of one of the most mile winters that I can remember. Our snow cover in northern Wisconsin is only inches deep and in fact I have quite a few bare spots on my lawn. With temperatures soaring into the 40′s (in January, no less) the snow really doesn’t have a chance.

Although the warm temps and mild weather is putting a damper on the outdoor snow activities, you can take advantage of the warm temps and beautiful sunny days to inspect and upgrade your antenna systems. Instead of climbing the tower when its unbearably hot, use this time to put up a new 2 meter J-Pole antenna. Or replace an aging antenna with something newer and better performing.

Did you get a new scanner or amateur radio transceiver for Christmas? Get it on the air with a base station antenna. Our J-Pole antennas make great scanner antennas, especially for the VHF public safety spectrum. My MURS J-Pole antenna is an ideal public safety antenna and will also perform double duty transmitting on the MURS radio band. Same story with the Marine Band J-Pole antenna. This antenna is tuned for the VHF marine band, but has enough bandwidth to cover the VHF public safety spectrum.

As the weather stays mild and the skies clear, use this time to enhance and upgrade your antenna system.