Coverage Maps - Opensignal in[@city]

Published Dec 24, 21
4 min read

For my fellow Canadians, here’s a great website which maps all the towers in Canada for multiple carriers and provides details, including their frequency band. You can also check with your mobile carrier and ask the technical support department for the nearest tower and its frequency band. Additionally, you can search your phone’s app store for “cell signal,” and multiple apps will pop up that can help.

In my case, the nearest Rogers cell tower is located in Bon Echo Provincial Park and operating at 850 MHz. With my research done, it was time to move on to gearing up for the build. Your basic list of required components consists of a tower, an outdoor antenna, an indoor antenna, a bi-directional amplifier, and RF cables.

By keeping the antenna highly focused, we ensure that all the signal power is directed at our target tower and not sprayed over a wide area. This is referred to as antenna gain and the higher the gain number the more focused the antenna power will be. The antenna I used is a 13 dbi gain 800 MHz Yagi antenna (fig.

Next up is our indoor antenna. We want to maximize indoor coverage hence the gain number will be much lower, as we aim wide, not far. Also, to keep household peace with the lady of the house, installing an ugly antenna on the wall was “not” an option for me, but luckily a ceiling mount was.

The one I used (fig. 5, Part #301123) can be found here. With both antennas in hand, you’ll need to pick out your bi-directional booster. With your booster, it’s all about GAIN and ensuring the gain can be adjusted accordingly. In my case, I picked up a 55 db gain amplifier (fig.

This worked perfectly and took my cabin from no coverage to 4-5 bars of coverage in any weather condition, including SNOW! That said, if the budget allows for a higher gain amplifier, go for it. The higher gain amplifier will provide better coverage, including the ability to drive more than one indoor antenna if a wider indoor coverage area is needed.

A good low loss 20-foot cable should have a loss of 1 db or less. And yes, a single db is significant. To put in perspective, a 3 db loss means that the signal power has been reduced by FIFTY percent…yes half! So every db counts, and ensuring one uses ultra-low loss cables is highly recommended if maximum coverage (gain) is needed.

As the outdoor antenna is highly directional and the indoor antenna is basically focused straight down below the outdoor antenna, we need to ensure that the outdoor antenna does not point over the indoor antenna, allowing for roughly 15 feet of vertical separation. These separation requirements get much stricter if non-directional outdoor antennas are used with panel indoor antennas.

This feedback is similar to audio feedback that occurs when a microphone (inside antenna) gets too close to the output speakers (outdoor antenna). If feedback does occur, your amplifier will shut down, so make sure that you space each antenna carefully. The tower itself is a simple thing to build.

I used 1 ¼” galvanized pipe in 6 foot sections for the tower (fig. 3) and a shorter 4 foot 2” pipe (fig. 2) to anchor into the ground. Although steel pipe would be cheaper, it also requires painting to ensure it does not rust, so I rejected that option.

Space the pipe away from the home’s foundation about the same distance as the upper strap you’ll use to secure the pole at the roof line. This will help ensure your tower is vertical and not leaning one way or the other. Having a directional antenna pointing 10 degrees down or up would not be good.

Don’t forget to attach your ultra-low loss cable and use electrical tape to strap the cable to the pole so wind does not cause the cable to wear. To get the height you need, simply add additional 6’ pole sections from the bottom up using couplers (shown in figure 3) to push the antenna higher while taping down the cable on the side of the pole.

In my case I have five 6’ sections holding up the antenna for a total height from the ground of 30’. Use galvanized strapping (fig. 4) at the roofline to secure the pole into position so it does not fall or sway to one side or the other. At the roofline, find a place (soffit vent or drill a hole) to feed the antenna cable into your attic/home and point the antenna roughly in the direction of the nearest cell tower.

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