Western Johnson County Field Test – 2020-07-26

Bill (KA2FNK) has been trying to orchestrate a field test between myself (KD0NRC) and Jay (WJ0X) for a few weeks. Jay and I live in Western Lenexa, KS — about 0.3 miles apart, but we both have antenna restrictions, and there are a number of structures between our homes. Bill’s initial survey tells the story pretty well. It doesn’t look promising.

Still, the distance is close enough, we had to try it just to say we did. Here’s a map also provided by KA2FNK.

Jay had not yet purchased any AREDN-capable mesh equipment yet, but KA2FNK brought along a Ubiquiti NanoStation M2 as well as a NanoStation LOCO M2 — a smaller, less-powerful, lower-cost unit. My initial setup on my end was using some painters’ poles attached together, with my Rocket M2 as high up in my driveway as I could get it. This was about 17 feet up in the air. Yeah, it’s sketchy. The antennae are some “high gain” omnidirectionals that I bought ages ago for wireless penetration testing with high-power Alfa adapters. They’re not optimal for mesh networking, but they’re what I’ve been using for years on this specific mesh node.

On WJOX’s end of the link, we set up a tripod on the upper level of the deck, and pointed the NanoStation M2 toward my place.

We moved it around the deck quite a bit, experimenting with locations and headings while watching the real-time signal graphs. From this end, we would see LQ (Link Quality) values in the 20-30% range, but 0% NLQ (Neighbor Link Quality). What this means is that there’s traffic flowing, but not bi-directionally. The antennae on the Rocket M2 at my place isn’t picking up the transmissions from the other end of the link.

I took KA2FNK’s LOCO M2 back to my place and replaced the Rocket M2 with the LOCO M2. The LOCO has lower power, but the integrated sector-antenna is likely better for longer-distance connections. Within a few minutes, we’d established a link!

I decided to try setting the Rocket M2 up again, but with a yagi-style antenna. This didn’t work very well at all, but when I moved the one omni-directional antennae to a horizontal position to get it out of the way of the yagi, I got a call over the radio that whatever I did helped. I re-attached the other rubber-ducky omni and aligned them parallel to the ground, or “horizontally polarized” if you will. I also moved the Rocket to a location that would be closer to a potentially-permanent mounting point.

The weather-resistant cover is missing here…

At that point, we noticed both LQ and NLQ quality metrics spiked pretty high, in the 70-95% range from both sides. This was better link quality than we got with the LOCO at my location. Parties on both ends of the link were able to browse other remote nodes (for example, I could access the GL.iNet USB150 that KA2FNK had plugged into his laptop, and KA2FNK could see the three nodes on my end, and access the WAN.

Here, I am browsing a remote device at WJ0X’s home, through 3 mesh hops:
my USB150 -> My Rocket M2 -> KA2FNK’s NanoStation 500 meters away -> KA2FNK’s USB150
It’s hard to tell from this angle, but the NanoStation is actually below the level of the structure, without any obstructions, other than the buildings between us.

At this point, we declared the the test a success. WJ0X is going to pick up a NanoStation M2 and we should have a permanent RF mesh link between our homes. The horizontal polarization thing is going to require some further investigation. The NanoStation and LOCO M2 both “look” like they’d have a vertically polarized signal, but evidence suggests they largely rely on horizontal-polarized signals.