Many cord-cutters rely on TV antennas to restore the local TV stations they lost when they gave up cable. TV reception can be tricky, though. Choose the wrong antenna and you won’t get everything available to you. So how do you know which local channels are available? And how do you know which kind of antenna to get? We’ll show you how to answer those questions using one of the go-to resources for cord-cutters: TV Fool reports.
It’s a bigger question than you think. There are more than fifty broadcast networks with local affiliates all across the country. Depending on where you live, you may get TV stations devoted to science fiction fans, English-speaking Millennial Hispanics, evangelical Christians and more.
TV Fool’s Radar Plot Report and TV Coverage Browser look intimidating at first. We’ll explain how these tools give you the information you need to get the most free TV possible.
Why is TV Fool Needed?
TV Fool launched at the end of 2009 to give people a handy web-based method for understanding local signal conditions in the aftermath of the American broadcast TV industry’s transition from analog to digital transmissions. Many people found that TV stations they used to get with their analog TVs wouldn’t show up on their digital TVs.
The kind of antenna you choose for your home, as well as where you place the antenna, can have huge effects on the number of channels your TV can get. Although there are a wide variety of antenna designs on the market, they largely fall within one of three categories:
- Omnidirectional: These antennas pick up signals from any direction, but work best with the relatively strong signals within 30 miles of local transmission towers.
- Multidirectional: At longer distances, with weaker signals, a multidirectional antenna concentrates signals from a general direction and ignores the rest.
- Directional: These antennas require careful alignment to pick up signals from a specific direction.
The location of an antenna also has a big effect on the quality of your TV signal. In general, the higher the antenna is, the more likely it will be to pick up a signal. You’re better off placing a small, flat omnidirectional antenna on top of a cabinet or taped to a window than setting it next to the television. An antenna in the attic would do a better job and a rooftop antenna even better.
Figuring out which you need is what the reports produced by the TV Fool website are for.
Radar Plot Report
TV Fool’s main tool is the Radar Plot Report. It estimates the reception conditions for all of the TV stations in your area. All you have to do is enter your location information to get a report like this one for Minneapolis, Minnesota:
At first glance, the Radar Plot Report can seem overwhelming – but don’t panic. The report is very straightforward. It consists of three parts: a table of signal information for each local station, a “radar” chart that helps plan your antenna placement, and a summary chart of signal strength at the bottom.
The report’s table gives you information on each signal you could receive at your home. In this example, TV Fool found fifty-one channels that people in Minneapolis might be able to get. Starting from the left-hand side of the table, the first four columns contain information about the TV station itself:
- Callsign: This is the FCC-assigned letters that uniquely identify each station.
- Real Channel: This is the actual broadcast channel based on its radio frequency.
- Virtual Channel: This is the digital channel that your TV may display.
- Network: Identifies the major national network the station is affiliated with, if any.
The first eight entries for Minneapolis are the major network affiliates. The remaining stations are either independent or affiliated with one of the more than fifty minor broadcast networks in the United States.
The next three columns in the table give you information about the strength and quality of the signal you might experience:
- NM: The Noise Margin lets you know how much room there is for interference the signal experiences along the way to the TV tuner.
- Pwr: The Power lets you know how strong the signal ought to be near your location.
- Path: This indicates how directly the signal reaches your location. LOS, or line-of-sight, is a direct path. The other options – 1Edge, 2Edge and Tropo – involve one or more reflections off of local hills or the atmosphere.
TV Fool considers Noise Margin to be the most important data point in this table. The color-coding of each row in the table is based on the Noise Margin.
- Above 35 decibels: Green. An indoor antenna in a typical suburban home can receive the signal.
- Above 15 decibels: Yellow. A larger antenna in the attic may be needed.
- Above -5 decibels: Pink. A rooftop antenna is required.
- Below -5 decibels: Grey. It will take “extreme measures” to get these weak signals.
In the case of our Minneapolis example, twenty-two of the stations fall well within the green zone where an indoor omnidirectional antenna should work fine. None fall within the yellow zone, while three within the pink zone would require a rooftop antenna. The other twenty-six have extremely weak signals – well into the grey zone – that would require an advanced setup to squeeze out reception:
You can see in the larger table that all of the green-coded stations have signals that follow a direct line-of-sight path while the other signals arrive indirectly from as far away as Bimidji, Minnesota, two hundred miles to the north.
The last three columns tell you the location of each TV station’s transmission tower. This usually has nothing to do with the TV station’s studios as towers are often situated in places like hilltops, skyscrapers or mountain ridges that let them cover wide swaths of the surrounding area.
- Dist – This is the distance from your location to the tower.
- Azimuth True – This is the number of degrees from true north, or what you would see on a map.
- Azimuth (Magn) – This is the number of degrees from magnetic north, or what you would see on a compass.
TV Fool calculates the compass bearing, the Magnetic Azimuth, for your convenience since that is often the way people figure out where to point their TV antenna. The need isn’t as obvious in a town as far north as Minneapolis. Take a look at this report from Miami:
Magnetic north and true north are off by a full seven degrees. That’s enough to make a difference between getting a station and losing the signal entirely. This happens because Earth’s magnetic north pole and its geological north pole are not in the same place. On top of that, the magnetic field lines aren’t straight so the “north” on a compass in one part of the country does not point in exactly the same direction as in another part of the country.
If you need to go with a rooftop directional antenna, this one little nuance in the TV Fool report could make all the difference when getting signals to your TV.
The report’s “radar” chart helps you decide the kind of antenna you need and its placement. With your home at the center of the chart, it shows where each station’s transmission tower is located.
Strong signals stretch from the outer rim of the chart almost all the way to the center. Weak signals, on the other hand, hug the edges. In our Minneapolis example, an indoor omnidirectional antenna will get all twenty-two local stations. Things look a lot different in the mountain town of Aspen, Colorado:
All of the TV signals are fairly weak and clustered towards the northwest. Picking up these signals would probably require a multi-directional rooftop antenna designed to collect signals from a tight range.
Channel strength table
Below the table and the radar plot is a chart of the TV stations’ signal strengths. Organized from left to right by broadcast channel, from VHF through UHF frequencies, it is simply a visual representation of the signal strength column in the report’s table.
Interactive TV Coverage Browser
TV Fool’s Interactive TV Coverage Browser provides a visual estimate of signal conditions for each station without the detailed data of the Radar Plot Report. The browser displays a list of stations and a Google map. As soon as you select a station it displays a color-coded coverage map.
The picture above shows what reception is like for a station near Los Alamos, New Mexico. The mountainous terrain has a significant effect on signal strength and creates odd situations where nearby locations have worse reception than distant locations.
There is little to interfere with the broadcast signal, however, in the relatively flat terrain surrounding our original example in Minneapolis:
Households far away from the city can, with the right antenna, pick up good quality signals. In fact, rural homeowners who happen to live near two major TV markets can often get forty, fifty, or more channels from a rooftop antenna.
TV Fool Reports: A Good Start
If you’re wondering why you’re having trouble with TV reception or are planning to get a TV antenna, a TV Fool report gives you a good estimate of reception conditions in your area. Just keep in mind that TV Fool’s reports are a starting point. Your ability to get the most local TV channels depends on many variables that a website just can’t predict:
- Trees: Leaves absorb TV signals. If you live in a wooded area your reception may be great in the winter but will suffer as summer approaches.
- Walls: The way your home is built can prevent you from using indoor antennas. The wire mesh used to create stucco walls acts like a radio shield that can turn your home into a quiet zone.
- Wires: The age and length of the coax cable running between the antenna and your TV, as well as the number of junction boxes along the path, can degrade the signal.
- Interference: Local construction, your microwave oven, cheap compact fluorescent lights and other sources of radio interference can degrade the TV signal even more.
Back in the days of analog TV, all of these issues merely made the picture quality worse. You might have to squint at a snowy picture and listen to static-filled audio, but you still got something. In our modern digital age, excessive noise in the signal can turn TV into an all-or-nothing proposition. You either get the channel or you don’t.
That’s why starting with a TV Fool report is such a big help. You can identify many issues up front before you buy and install your antenna. After that, it’s just a matter of troubleshooting the smaller issues to ensure you get the most TV channels possible.
Chris Casper is a former tech industry product manager who escaped from California for New Mexico. Now he writes about science and tech while searching for the perfect green chile sauce.