My QTH's visual horizon

Let's take a look at my QTH, compared to two previous locations:

This obviously home-brewed composite chart shows the terrain elevations at all compass points around three sites I have used since my return to contesting in June 2002.

The data was generated by Radio Mobile software using a viewing height of 100 kilometers -- meaning it takes into consideration all topography within a 50 kilometer radius.

Here's what the squiggly lines are really saying:

• The blue line (labelled LODGE) is my Winfield, BC, QTH prior to April 2004. It shows the signal-blocking mountain due east of the house -- it blocked signals below 12 or 13 degrees for about half of the eastern horizon. I was never able to get any antenna higher than 30 feet there, which only made matters worse as all I was able to hear were high-angle close-in signals. Not a great situation for a contest station.

• The aqua-green line (FARM) is the contest location I set up at my parents' ranch in the hills west of Summerland, BC. Used this site for about 6 major contests from summer 2002 to Feb. 2004. As you can see, it also had bigger mountain problems than my home QTH. Why did I use this site? Mostly because it had a LOT of 90-foot pine trees and at least I was able to get my wire antennas high in the air. Earned my best scores from there, despite its proximity to high mountains in key directions.

• The red line (OK CTR) is my new QTH, about 2 kilometers due west from the old QTH. The mountain is still there, but it's a lot lower on the horizon. Signals above 6 degrees are unobstructed from the east. Note the dip at 20-30 degree beam headings -- a nearly perfect shot into Europe. I am writing this on March 13, two weeks before we move to the new house. It's on 1 acre of land with tall pines at one end. I intend to build a much more competitive contest station there. As they say, please stay tuned.

Subsequent analysis (see my great circle bearing map) used a 25-km height (12.5-km radius) and shows slightly better results for the new QTH and even worse results for the old location.

Radio Mobile software
Essential free program to find out where your station's best directions are for working DX (and contesting). Tell the software your latitude and longitude, and it will go on the Internet, download the topographic data and display a color map of your area. The "Visual Horizon" tool will graph the highest elevation in a circle around your QTH.

Great Circle Bearing Map Software
I used GCMwin to create the great circle bearing maps for my QTH analysis. Great software, and it's free, too.