BackCountry Wifi; Part 2
Wither the Sun
Once when I was a kid, I went on a summer-camp field trip to Disneyland, and more than anything I was captivated by the Pirates of the Caribbean ride. My friends and I rode it over and over again, imagining what it would be like if we were able to jump out of the boat and take up permanent residence on an island of treasure say, or among the sword-wielding brigands in their perpetual sway. The notion of becoming part of that place overspilled my heart with longing to the extent that it’s about the only memory I have of that day.
That’s what it feels like to live here. As if finally I’ve leapt off that infernal, too-fast-floating prison raft on the pirates of the Caribbean ride. And having done so, I’ve found— rather than animatronic veneer — a place even more authentic, and incredible than it looked from the boat. And so deep — so grand-canyon, outer-space, Barry White deep — that I know I could spend the rest of my life exploring it without ever being able to claim: I know this place.
The people who live here measure their success not in dollars and cents, but rather by their capability to not have to leave. They reluctantly admit, for example that they leave daily to drop their kids off at school say, or that they finally relented and drove to town yesterday for coffee.
To have no need of ever coming back is something of a universally shared, unspoken fantasy among us. One around which the people here, however consciously, plan their lives. I am so luckily situated in this respect. I have no kids for school; no car-dealership to manage, no delivery-route of eggs or bread. In the economy of this place I am filthy-ass rich.
All I need to do is construct a 15-mile-long self-sustaining, weatherproof wifi network, and Cynthia and I can remain as long as the food holds out. My neighbors may not understand what all of my odd-looking antenna’s do, but they intimately empathize with the tantalizing possibilities of my profession. Once this is wired up, we won’t have to leave. Not every day anyway, or even every month if we’re careful.
And so it is, the ranch hands gather with curious children and happy dogs in tow at the trailhead to Broker’s Knob to lend us a hand. It is hunting season, so we chat about Elk as they load their snowmobile sled with my solar panels and batteries, before hauling it all up in two loads. Two bulls were seen up by the Thorntons gate last evening, and the deer are still visiting the apple tree down by the community center, even despite the fact it has no more apples to give. No one talks of anything but hunting season in hunting season.
When I carefully set the panels onto the sled, the pungent sent of weed fills my nostrils. Everything — the panels, the electronics and batteries, the waterproof boxes — everything reeks of Marijuanna. With the weather, it’s all been in my workshop for weeks you see. My shop has a Spartan beauty about it, having been built as a wood-shop by the original owner of my home, who made his own furniture. The man I bought it from, however, had been using it as a large grow-room; a matter of infamy in the neighborhood, and an avocation from which I fear it will never recover in terms of fetor.
If anyone notices, they don’t let on. Their collective attention never wavering very far from the subject of hunting anyway. They keep randomly wandering off to follow elk or deer sign, or to scope across the canyon at this or that game trail, nodding knowingly at each other. Despite the periodic unplanned absences, we finally get everything assembled and wired up.
A lot has changed since I first spec’d out the relay this summer, but probably the most important difference is the parabolic dish antenna at the top of the post, rather than the 10db Yagi pictured in Part 1. The new antenna is actually the property of my very favorite internet service provider in the universe: WispWest, who not only agreed to support me in my somewhat non-standard installation, but even allowed me to install their pre-configured dmarc hardware myself. Seriously; thanks uguise.
Like most engineering solutions, solar power is a question of balancing and trade-offs. The real ;tldr is that batteries suck. Get them too hot or give them too much current and they explode. Get them too cold or give them too little and they die. If you can afford them they’re too heavy. If you can lift them, they’re either not powerful enough, or too expensive. When I first did the math on what I’d need, I came away thinking 100watts of panel and 100 amp-hours of battery would suffice.
After some input from the experts, I wound up with 300 watts of panel, and 200 amp-hours of battery. Did you know that it’s actually possible to have too many batteries? It turns out, if you have so many batteries that you can’t charge them all the way up every day, that discharge/fraction-charge cycle can destroy them too. Batteries suck.
Everything you need to run two high-powered Ubiquiti antenna’s on a mountain top, you can get from Amazon for a few hundred bucks. Pictured here is a Victron MPPT 75/15 charge controller, a bus-bar and fuse box, a 12–24v step-up transformer, and a POE-injector (on the far right) — all purchased on the big-A.
The Victron was another excellent suggestion from the ubnt community forums. They’re very hacky and the team behind them has a github site, links to OSS projects, and etc. I got the large plastic tool-box from Walmart, and the foam-cooler beneath the board housing the batteries I found in the garage.
The system is pretty well balanced. It usually fully charges the batteries within four hours of sunrise. The panels rarely even approach half capacity, meaning I could add a few more batteries if I really want to bomb-proof things (which I do).
Once we got the panels assembled and wired up, everyone scattered, and I came down the mountain for lunch. Then, when I returned an hour or so later with a 40-lb load of t-stakes and sledgehammer to wind-proof everything, I found fresh Mountain-lion tracks everywhere. My neighbor Rusty, who knows things about mountain-lions, explained that the northern hillside of our valley contains the highest concentration of mountain-lions in Montana. He went on to describe in vivid detail how the large cats like to sun themselves on the rocky ridge-lines around Broker’s Knob, and how this cat had likely been lazily watching us the entire time, just waiting until we left to casually make his way over and have a sniff at my little repeater site. I know he intended at least some of these details to frighten us, but we come away feeling blessed by the visit.
All the same, I’d appreciate it if you don’t mention any of that to my father-in-law.
That night (of course) it snowed. We got 5 inches that night; coating both panels with wind-blown snow, and blotting out the sun.
In spite of the weather and to my wife’s chagrin, I insisted on hiking up as early as possible to see what the light looked like and how the panels were responding. To my relief, not only had the 40mph winds not blown everything away, but the panels were pulling 40 watts in bulk-charge mode despite the light you see in the picture/video above.
As I write this, the primary hop on Broker’s knob has been stable for a month (the second hop still needs some refactoring). I even have some nascent monitoring going on:
In the next and hopefully final article I hope to have the second hop dialed in completely, and to add a single-board computer on Broker’s Knob to monitor the charge controller and other environmentals. But for now, give or take a conference or two, and taking into account the current supply of coffee, I am operational and working from my front porch. I don’t have to leave.
Not for a while anyway.