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(A shorter version of this was published in issue #88, April/May
2002, of Home Power Magazine)
Overview of the projectBecause the nearest phone line is a mile away, I wound up installing a wireless phone system at my off-grid house. Not a cordless phone, but a long-range wireless system. I wound up installing a Telemobile PTEL system. This is a 4watt UHF based system with a range of about 20 miles, line of sight. The local phone company gave me some huge number for a quote, and at the same time, I didn't really feel like digging up the street to run a very expensive phone line, when good satellite technology is just around the corner, and their are good wireless solutions available now.
Once I had this info, I then plotted the data from the GPS a Garmin Map 12) on my PC using the TopoMap mapping software. This is a collection of 7.5 (1:25000) scale Topo maps that one can plot GPS data on. For me, the main thing I wanted to do was to plot out the line-of-sight between my house, and each phone box. Although I had done signal strength tests with my UHF, the TopoMap software lets one take a route, and then plot the profile, as opposed to a regular map view. This let me see very plainly any obstructing things, like a hill top, rock outcroppings, etc... At this point I had the info distilled down to 3-4 prefered sites, anyone of which would work. I then contacted the owners of the best location. I couldn't get Qwest permission to install anything on a Qwest pole, so I had to install things on private property. Using a landline on private property saved me from months of arguing with my local phone company about access to one of their poles for my antenna and transceiver. The owners of the property were very supportive, and then I ordered another phone line at their address, that gets billed to me. Once the phone line was hooked up, Qwest had to spend 7 days fixing the trunk lines, as my location was literally at the end of the phone cable. Then I had to scout out a place on the hillside near the phone box for the underground cable.
I finally settled on a small meadow about 85 feet uphill from the box. I then setup my existing portable power system, as I ordered the parts for a permanant power system, but I have to wait for them to arrive. My portable system is a 235AH system I use for a portable UHF backcountry repeater. Once Qwest had fixed the trunk lines to this location, I could pop the cover off the green box where the landline comes out of the ground, and using a telephone handset, modified to work as line tester, I found I had a dial tone! Then I spliced a 100ft, standard phone cable into the wire pair for one one line. Finally I hooked that cable into my power system and transceiver. After I set the antenna up on a short mast, I called the house via a poor cell phone connection, and it worked! Then we discovered "the problem". The problem was that after a phone call, the line would short out, and no phone calls could be made until it was cleared by Qwest. They kept telling me it was a problem in my system, and all my tests kept showing the problem was on their end. The problem was even worse, because they have no experience with wireless phone systems of this type, so they were convinced the problem was somewhere in my system. Luckily my 25 background as a phone phreak came in handy. After 2 weeks of arguing, with me running many tests, I finally convinced them it was their problem, and suddenly they found a bad circuit board, miles from my house! Once that was replaced, it worked reliably for about 2 weeks.
The phone actually went down all the way once in my system, when the Lyncom charge controller showed an unexpected problem dealing with cold temperatures. (like about -40F) It had good timing, cause it died in the morning, and that afternoon the new SOLSUM charge controller I had ordered showed up via UPS! It figures that I get this system online, and then get hit with Colorado's coldest fall this century... and my domes are at 8800 feet in the Rockies. I had another problem on my end, but it didn't bring the system down at all. It turns out the Trojan T-125s I use in my portable repeater power system also weren't dealing well with the cold. I had heard of other folks putting light bulbs in with their Telemobile systems, and even a few of those I'd heard were off the grid. But I couldn't track down any real info, and didn't want to build a huge power system to run a heat source as well. The sub zero temperatures for days on end, combinded with a week of overcast, snowy weather really drained the batteries. When the Deka 280AH Gell Cell I had ordered finally arrived after weeks stuck on a loading dock in Denver, I decided to replace the battery right away, before I lost vehicle access to the spot where my landline is. There is no way I'd be able to carry a 135lbs battery to the site. The Gell Cell was rated to -40F, so I guess we'll see...
The portable Power System
This system produces about 100 watts, powered by a UniSolar
unbreakable 64 watt panel and a UniSolar 32 watt flexible panel from
Jade Mountain, and
2 - 235 Amp Hour (6 VDC) Trojan T-125 deep
cycle batteries, along with a 24 Amp Lyncom charge controller. I
didn't use the 32Watt flec panel for the phone though.This system was configured to run a 4watt UHF Ham radio repeater at Rainbow Gatherings, and gets heavy use during emergencies, and at other times. So it's a bit over powered, but oriented to running a repeater, which draws 300 milliamp during standby, and only 3A during transmit. This system was designed somewhat from a seat of the pants, perspective, but has worked good for both the repeater, and it's temporary use for the phone. It's just oriented for summer use, and the 2 T-125s are used, cause at 60lbs, they're carriable by a human to whereever I set the repeater up. More info on the repeater is on this page I did on Backcountry Radio Systems, in my case, more oriented towards Search and Rescue kinds of activities. The box was lined with closed cell foam all around, and a 2 inch thick piece of styrofoam for the base. I then cut holes for the phone line input, the antenna coax, and the power line from the solar panel. The entire system is housed in a PortaPak plastic container, which I found seals the best, and had good handles for the locks. I then chained the box through both the handles to a tree. While this is a remote location, I still wanted to be careful to prevent easy vandalism.
The Permanant Power System
The permanent system is a little different than the portable one. The
permanent system has a smaller charge controller, a SOLSUM 5.0, cause
the Lyncom I bought in case I needed it to jumpstart the house
someday. The SOLSUM only handles 5 Amps. I also got a Deka 280AH Gell
Cell battery. The Gell Cell will deal much better with the cold weather
(-40F) that we get around here. I also ordered a new Unisolar
unbreakable 64 watt panel. I ordered this stuff from Rocky Mountain Solar, a friend
who now distributes alternate energy stuff.
This system was much more "designed". I used the spreadsheets I wrote for power system sizing, and the correct wire gauge to work out the specs. These spreadsheets are on my software page. I had several problems with the battery. First, the shipping company refused to come down my road, because the didn't think their truck would make it down the 1 mile long private drive. So I had to met them in town, and the two of us loaded the battery directly into my little Toyota truck. Then it was huge, and I was hoping I got all the measurements right, so I could put it in the same plastic box I'd been using. Abel and I managed to get it from the sled, into the box, and it just barely inside the insulation, but it did. Whew.
How it's worked outSo far it's worked worked pretty good. The main problem is my antenna coax at the house end runs too close to the invertor power feed, which causes some 60Hz hum in the phone line. We've also discovered a problem with heavy loads. If I run the large 1400 Watt Miter Saw (I've been laying a floor, and building walls) during the day when there is plenty of excess power, things work OK, althought the saw makes a noise on the phone line. But if I try to do this at night, when running 100% off the batteries, running the saw will disconnect the call. This hasn't been to inconvienient, I just have to make sure I don't saw anything when anyone is on the phone.For awhile, I've been trying to get my computer modem to successfully connect over the wireless phone. I've discovered several problems. The first problem was my older PCMCIA modems wouldn't recognize the dial tone. This was easy to fix by buying a new modem. As a backup, I got one with cell phone support as well. That solved the dial-tone problem. The I had the problem that I couldn't actually connect. The modem would go through all of it's initialization tones, and then finally give up. This turned out to be a problem with the buzz on the phone line. This buzz is caused by the inverter. I'm about to try putting a noise-limiter on the 12VDC power line, but for now, I just flip the AC disconnect off, and the line is quiet enough to connect at around 14.4 - 19.2 baud. At the least, it sure beats sitting on a rock outcropping with my cell phone in January to check email!
Update March 22, 2003Well, another Lyncom controller fries... This is the second one I've had problems with. They seem to be sensitive to cold, (like -20F) weather. The problem was I had the PTEL tranceiver hooked up directly to the battery, cause with the now dead Lyncom, it would actually put a buzz on the line when it was connected to the load. It probably needs a noise limiter like I have on the other end. Anyway, we noticed cause one day the phone died, and when I snow-shoed in, the battery was at 6VDC! Ahhh!On another snow-shoing trip into a few days later, I swapped in my other Lyncom charge controller. This when then failed in a similar way. By now, I was getting tired of snow-shoing in, since I had made several other trips to hook the PV panel directly to the phone, where it would run PV direct. At least that way, we'd have communications when the sun was shining. I asked around, and finally bought a MorningStar SunSaver 10A charge controller. I snow-shoed back in yet again, and installed it. Unfortunately, it started snowing heavily, and didn't stop will we had literally 6 feet of fresh snow! So it hadn't gotten any sun, and since the battery was low, the phone was dead during the entire blizzard. Once the snow had stoppped, we knew the panel would be buried, so my son snow-shoed in, for a nice change of pace, and dug out the panel so the battery would charge.
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