Listen to cops, pilots and truckers by turning your phone into the ultimate radio

You’re starting on page 2 of this, click here to start at the beginning.

What is SDR?

SDR stands for Software Defined Radio. To understand how SDR works, let’s first explain how a radio system works. Just like the AM or FM radio in your car or stereo, you can send transmissions of music, conversations, and data over radio frequencies. When you tune to 95.5MHz on your FM radio, you’re tuning your radio to the 95.5MHz frequency, picking up the channel of your local radio station and its music. The handheld radios you see used by campers or law enforcement work the same way, tuning to a specific radio frequency that their devices are capable of from their internal hardware.

Software Defined Radio works the same way, but uses a computer to process the incoming radio signals instead of internal hardware. This gives access to a far greater range of frequencies, though most SDR systems can also cost hundreds of dollars. However, back in 2012 a group of hackers found a way to use the cheap, readily available RTL2832 DVB-TV adapter as an SDR. This RTL-SDR gives access to monitoring frequencies between 25MHz and 1700MHz, but costs only about $30 to create if you already own an Android device or PC. It’s also easy to get started with, since it only needs a USB adapter and some extra software. Look at the video below for a demonstration of RTL-SDR on Android:

Is this legal?

This is usually legal, but it depends on what you plan to do with your RTL-SDR. Here in the United States, the FCC allows you to listen in to unencrypted frequencies as long as you do not transmit, which isn’t possible with RTL-SDR anyway. It’s also important to check up on your local and state laws, as each area has different rules about how you can use scanners, especially if you plan to listen in to local law enforcement. Several states also restrict usage of scanners in vehicles unless you have an FCC amateur radio license.

It’s best to buy your RTL-SDR adapter from a trusted source to ensure you have ESD protection.

No matter what, do not use RTL-SDR to listen to GSM or cellular telephone frequencies. Although it is possible to reach these frequencies with RTL-SDR, the FCC forbids monitoring such communications, as well as attempting to listen into or decode encrypted frequencies. We know you wouldn’t try to listen in on people talking on their phones, but when in doubt, check the FCC’s spectrum map. The spectrum map includes an explanation of each frequency band and who is authorized to use it.

If you plan to use RTL-SDR as more than just a fun weekend project, we also recommend you consider obtaining a amateur radio license, which will allow you to transmit on certain frequencies. The ARRL website provides plenty of useful information to learn about getting an amateur radio license in the United States. If you’re just looking to get started and see what you can do with an RTL-SDR, then follow this guide to get started with RTL-SDR on Android.

Click on a link to jump to a section, or click to the next page:

Next Page: What equipment and software do you need to get started?

Home Theater

Sony’s 360 Reality Audio is the epic sound revolution you didn’t know you needed

After Sony’s utterly bizarre press conference, I almost missed what was perhaps the most impactful sonic experience at the show. Luckily, I went back to Sony’s booth on the last day of the show, only to have my mind blown.
Home Theater

These awesome A/V receivers will swarm you with surround sound at any budget

There is no one-size-fits-all approach to shopping for a receiver, so we assembled our favorites for 2018, at multiple price points and all loaded with features, from Dolby Atmos to 4K HDR, and much more.
Home Theater

Banish the bunny ears (and monthly bills) with these excellent HD antennas

When transitioning away from cable and satellite, finding the best HDTV antenna for your area can be touch. To help, we've compiled our picks of the best indoor HDTV antennas you can buy.

Don't use streaming apps? Try the best free media players for your local music

Rather than using music-streaming apps, you may want something for playing your local music. Good news! There are some good alternatives. These are the best media players you can download for free on Windows.

The most expensive Galaxy S10 could be the priciest Galaxy phone we've seen

Not long now; with 2019 underway, the Samsung Galaxy S10 is almost here. Before it arrives, here's absolutely everything you need to know about all three of Samsung's next flagships.

Yes, Android apps can run on your PC, and it's easier than you think

Wish you knew how to run Android apps in Windows? It's easier than you might think and there are a number of different ways to do it. In this guide, we break down the steps so you can follow along with ease.
Emerging Tech

CES 2019 recap: All the trends, products, and gadgets you missed

CES 2019 didn’t just give us a taste of the future, it offered a five-course meal. From 8K and Micro LED televisions to smart toilets, the show delivered with all the amazing gadgetry you could ask for. Here’s a look at all the big…

Unleash your inner artist with the best drawing apps for the iPad Pro

The best drawing apps for the iPad Pro turn Apple's robust tablet into a canvas worthy of a true artist. Here are 20 of our current favorites, whether you're looking to keep things simple or take your art to the next level.

Mobile World Congress (MWC) 2019: Complete Coverage

There's no bigger show for mobile tech geeks than Mobile World Congress in Barcelona, Spain: where flagship phones are born and intriguing new wearables shine. And this year, where foldable phones and 5G are likely to dominate the news. For…

C you soon? Rumors swirl of a USB-C port on 2019 iPhones

While it's not been long since the last iPhones launched, rumors for the next iPhone are already surfacing. Apple's 2019 flagship could include a variety of upgrades ranging from a new design to enhanced features.

Biometric phone unlocks can’t be forced by feds, says U.S. judge

Fingerprint and face unlocks used to not be protected by the Fifth Amendment, but that may soon change. A judge in California has ruled biometric unlocking methods of all kinds are protected in the same way as passcodes.

The Note 8 and S8 range now have access to the Android Pie beta

Android 9.0 Pie has been released. But is your phone getting Android 9.0 Pie, and if so, when? We've done the hard work and asked every device manufacturer to see when their devices would be getting the update.

The Motorola Razr may return as a foldable phone — for $1,500

The Motorola Razr V3 is one of the world's most iconic phones, and it could be making a stylistic return in the form of a foldable Motorola smartphone -- but it may cost around $1,500. Is the nostalgia worth it?

The iPhone XS Battery Case's battery has a smaller capacity than previous cases

Apple has been rumored to be working on a new iPhone battery case for the iPhone XS, iPhone XS Max, and iPhone XR. Now, those new cases are finally here, offering seven hours of extra use for each iPhone and are available for $129.
2 of 5