All,
In my previous post I mentioned I was doing some preliminary range modeling — this post covers exactly that.
I started out thinking like a typical ham — high is good, higher is better. But from my experience with the Club and our repeaters, I know that getting antennas significantly higher than head height is really hard. You run into change of management issues, unrealistic insurance requirements for climbers, and difficulty even securing a climber. It’s 100% a PITA.
So, scratching my chin and working with Matthew Murphy (KF5NRU), I asked him to run some different configurations in the modeling tool. For sake of argument, we started with hypothetical devices at his tower location and the Lamar County Courthouse (119 N Main) at 50 feet elevation. Here’s the visual depiction of that simulation:
Center-to-center of the blue areas is a little under 7.5 miles. And when I zoomed in on that image, the transparency wasn’t perfect, but I could make out the loop. Here are two closer images — one without my red line and one with it. The red line traces just outside the loop to help it stand out:
Wow… I was not expecting that. The model shows that a single device at the courthouse at 50′ would cover the entire area inside the loop. That’s a lunchbox-sized unit for under $100, solar-charged and autonomous.
Now, let me temper this — I do not believe one $100 device will magically cover the whole area in real life. This is just one model we’re looking at. There are other tools and many variables we can adjust.
My real point is this: Rather than relying on one high-up device at the courthouse, if we sprinkle nodes around the Paris area (for example at Club members’ homes) at more reasonable heights, we can still achieve excellent coverage. Matt and I then modeled 3 meters (about 9–10 feet) and here’s the result:
As you can see, the lower height reduces the range, but not enough to kill the idea. Dispersing a number of nodes at lower, easier-to-achieve heights is much more practical, faster to deploy, and adds redundancy. No single point of failure.
It’s as simple as asking: “Who’s willing to buy one and put it at their house?” If we get a handful of people spread out across the area, they can mount them on a roof, shop roof, tower leg, or whatever they have available — all at ladder height.
As time allows, I’ll start modeling where Club members live to figure out optimal node placement — minimizing the number needed while maximizing coverage. I’ll probably run most of these at 3 meters (10 feet) just to keep it realistic. Of course, if anyone can go higher than 10 feet, even better!
73 Phillip Beall (W5EBC)