Two-Way & Amateur Radio

Picture this: You are at some kind of street event, and the cops cut everyone's cell phone signal. No more data. No more Telegram. No more Signal. Or you are out in the middle of nowhere, suffer a crazy injury, and you are not in range of any cell towers? Maybe this is the ocean, or up in the mountains. Maybe a hurricane has rolled through town, cut off the route to the hospital, and your neighbor is about to deliver their child. What do you do?

In ancient times, people once used a magical device called a two-way radio to communicate. In fact, many still do and do not know it. The cell phone you use today is just a computer with a few radio components, but it operates on the very same Radio Spectrum as your television, home wifi and car radio - just in a part of the spectrum set aside for cell phones. Big Cell Phone doesn't want you to know this, but there are still places set aside for people to talk to each other with the old-fashioned radios anonymously & for free!

The physical reality is that it is impossible to completely lock down the radio spectrum: It is just a big open thing that exists all around us which anyone can throw things into. And all you need is a cheap walkie-talkie to get started.

Many different types of radios are share the same radio spectrum. A planet-wide gentleman's agreement is all that keeps it from descending into total anarchy.

While all radios operate on the same spectrum, they generally only work on very specific parts of that spectrum where they were designed to operate (ie: your car's FM radio will only pick up FM stations, or your wifi adapter only communicates with other wifi devices on the wifi frequencies). Some radios are forever locked into specific frequencies and modes, and these are the only places they will work even if you try to hack them.

However, some radios are capable of a lot more than others, and can work all over the spectrum. Some of them can transmit in all sorts of wacky modes, and completely overpower regular communications on those frequencies. A litany of fragile federal laws & international treaties, enforced only by threat of retaliation, are all that keep the radio spectrum from being rendered unusable for everyone. This works by decreeing (or allocating) specifically defined chunks of spectrum space to specific types of radios and communication methods. You can see detailed allocation decrees at RadioReference.

Heads Up: If you choose to broadcast on a part of the radio spectrum you are not allowed to broadcast on, expect someone to eventually hunt you down for sport! For example, if you:

• Talk on amateur radio bands without a license;
• Regularly transmit at wattage far in excess of what is legally allowed;
• Interrupt frequencies set aside for cell phones and commercial radio stations;
• Harass pilots and/or air traffic control, or harass shipyards;
• Mess with orders at the same fast-food drive thru every day;
• Hit police channels with endless loops of the hit 1992 Body Count song 'Cop Killer';
• Broadcast curious number patterns on 4625 kHz;
• Issue fake weather alerts on the NOAA channels;

…then be aware that on a long enough timescale, someone will be bored enough to try and find you. In some places, this can take no time at all. Many people who are into amateur radio have spent tens of thousands of dollars on equipment for this rabbit hole of a hobby. They are always looking for ways to play with their expensive toys, and one of these ways is by triangulating the origin of rogue signals and reporting them to the government. Some of these people also work for the government. Be careful out there!

LEGAL NOTICE: THIS PAGE IS PROVIDED FOR REFERENCE PURPOSES ONLY. THE ANONYMOUS MILITARY INSTITUTE DOES NOT ENDORSE UNAUTHORIZED AND/OR ILLEGAL RADIO USE, OR USING ANY OF THESE RADIOS IN PLACES THEY WERE NOT DESIGNED OR APPROVED FOR.

There are many types of two-way radios, and not all of them will be practical for your specific use case. Here are the ones you are most likely to encounter:

FRS/GMRS frequencies & power limits.

The Family Radio Service (FRS) and General Mobile Radio Service (GMRS) are a set of overlapping radio bands in the UHF range, which both use the same sets of frequencies around 462 MHz and 467 MHz. The consumer walkie talkies that you will see at Walmart and outdoor supply stores in America (like the Motorola Talkabout series) are just simple FRS/GMRS walkie-talkies.

The difference between them, is that GMRS radios can legally be more powerful, and they have access to a few extra frequencies that FRS radios can not. GMRS also has allocation for repeaters, which FRS cannot use. FRS radios are completely free to use, but GMRS radios require a license. The license is $35 and there is no exam. The license covers you and your extended family for 10 years, and it covers every single one of your family's GMRS radios. Unlike amateur radio licenses, nobody ever checks for this license, because the license-free FRS radios operate on the same exact channels.

These radios are a bit limited in what they can do, but they can be found cheap, they work right out of the box, and you can program fancier radios to work alongside them. They make great spare handhelds to have lying around for those times you have to work with someone that doesn't know anything about how radio works.

Behold, the handheld that renewed interest in the humble dual-band: The $25 Baofeng UV-5R.

Popular in recent years, is the dual-band radio. These radios are essentially amateur radios designed to work on VHF and UHF radio bands. The frequency range of these radios varies from unit to unit, depending on the manufacturer and their whims at the time, but this usually means they can pick up a bunch of frequencies around 130 MHz to 180 MHz (part of the VHF range) and another set around 400 MHz to 500 MHz (part of the UHF range).

In layman's terms, this means they can be used to communicate with FRS/GMRS radios and 70 centimeter amateur radios on the UHF range, as well as MURS radios, marine radios, Airband radios and 2 meter amateur radios on the VHF range. Technically, using these to transmit on FRS/GMRS/MURS/Marine/Airband channels is illegal. If you have an amateur radio license, you can legally use these on the amateur bands, as they were designed for. Of course, if you are only listening, that doesn't require a license at all.

Dual-band radios may even have transmit capabilities on a third or fourth band (like the 200 MHz range), and some can even listen in on the entire spectrum from 50 MHz to 600 MHz. Many of them feature the ability to keep the radio tuned into two stations at once, enabling you to simultaneously remain in contact with different types of radio users. There are also some cases where the UHF channels will perform better on the field, and other times when the VHF channels will be better - this depends on terrain, obstacles, clear line of sight, etc. The general rule-of-thumb is that VHF rules the sea & other wide open spaces, whereas UHF is more preferable in buildings & cities. Being able to use both keeps your options open no matter how the day goes. They are useful if you travel as well, as they are roughly compatible with the civilian radio allocations in many other countries: Just program in the set of default channels people use in that country, and you are good to go.

Some of these radios are not even walkie-talkies at all, but come in box form, to be mounted on your desk or in your car with a large external antenna. These types of radios will have better reception, better sound quality and a much further range than handhelds.

The UV-K5/K6 series supports custom firmware & a large range of frequencies.

A handheld dual-band is an incredibly versatile tool. Depending on the radio, they support a range of antennas, headphones/earpieces, and power options. With the right accessories, you can even mount them to your clothes or backpack with tactical webbing. All of these support the use of CHIRP for relatively painless programming.

• The UV-K5 and UV-K6 by Quansheng/Anysecu are very cheap 5-watt handhelds. They are at the top of this list because you can easily swap out firmware, giving them toys like spectrum analyzers, reception of everything from 50-600 MHz, and a slew of other neat functions. Some firmwares unlock them further, allowing them to transmit on additional bands. As IEEE Spectrum recently remarked: "The Most Hackable Ham Radio Yet".
  • For those starting out, we highly recommend egzumer/uv-k5-firmware-custom, as it supports painless flashing via Chrome-based web browsers. It is packed with features, makes the interface on the tiny K5/K6 screens far easier to read, and it comes with the aforementioned spectrum analyzer mod that makes these great scouting radios for discovering transmissions.
  • If you are really daring, you can give whosmatt/uvmod a shot. This gives you a more fine-tuned selection of various firmware mods. Chances are the aforementioned ezgumer firmware will be enough for you, so we only recommend uvmod for power users.

• If you are a novice and the idea of flashing your radio's firmware sounds daunting, the 5-watt QYT KT-8R is a great first handheld to play with. It has a large easy-to-read color screen, supports a wide range of frequenceies, and it can listen to 4 channels simultaneously. This makes it a great first-time radio to start on, as you can upgrade to a dual-band such as the aforementioned K5/K6 series later, and still keep the KT-8R around as a practical secondary radio. Why would you want two handheld radios? Because between the KT-8R and a normal dual-band, that means you can monitor six frequencies at the same time, which is obscenely useful in crowded urban areas.

• The TD-H3 and TD-H8 by Tidradio is another popular handheld series that can be unlocked with custom firmware. The 5-watt H3 costs marginally more than the K5/K6, but offers full-color backlit screens in a slightly more compact form factor. The larger H8 costs a little more, but has a whopping 10 watts of broadcasting power. The custom firmware options are not as fully developed or easy-to-install as the K5/K6 yet, but hackers are already on it so we expect these to become quite versatile handhelds in the near future.

• Baofeng has a massive line notoriously cheap handheld VHF/UHF radios. Baofeng was who renewed the world's interest in dual band radios, because you could get a UV-5R for $25, and program it on your computer to pick up a whole bunch of different things, when comparable walkie-talkies cost over $100. Nowadays, you can find better handhelds for comparable prices (see above), but these things are everywhere. Other popular models include the UV-82 series, and more recently, the UV-17R & UV-5RM series. These aren't the most precise radios. They're also dirt cheap. You won't mind if you lose one down the side of a mountain, or into the sea, or if it gets stolen. Three important notes:
  1. Most of these radios have the same frequency ranges. Others are more limited. Check the specifications before you order, to see what frequencies that specific model can access, as this can sometimes vary wildly from model to model, and even different production runs of the same model. You can program these, but they are harder to unlock, and many of them cannot be unlocked.
  2. Most of these are 5-watts, though some models boast up to 8-watts of power. Again, you'll have to research this yourself. There are simply too many Boafeng models and sub-models to catalogue here, and all of them (even the “high power” ones) are entry-level radios at best.
  3. Watch out for knockoff Baofeng hardware, as there is a lot of it. Only trust direct sellers of Baofeng (and BTECH) products. Be especially wary for counterfeit USB cables, as not every programming cable that carries the Baofeng logo will actually be able to program your radio.

One final important note: Just because you can unlock some of these radios to use all the frequency bands, doesn't mean you will get good performance on these bands! This is especially applicable to those using custom firmware on the K5/K6 series trying to transmit on 50 MHz. The chips in these radios simply were not designed for that kind of use. Reception is one thing (and child's play for the tuners) but as far as transmission goes, stick to what the radio was designed for if you want other people to actually hear you!

Mobile radios offer greater range than their handheld counterparts.

If you need greater range and better audio quality, you will want to upgrade to a full-size radio wired to a big outdoor antenna. These types of radios are great for vehicles and home base stations, or anywhere else that you have room to daisy chain a bunch of radio hardware together with a real power source. They also cost quite a bit of money compared to a handheld, especially once you get into the high-end ones. Here are some relatively affordable starting points.

Note: These types of radios are usually designed to be used with a vehicle's DC power system - Indeed, they are normally sold as “mobile radios” to set them apart from handhelds. If you plan on running one of these radios at home, you will need a AC to DC power converter (which is NOT to be confused with the DC/AC inverters that let you run household electronics in your car).

• The Retevis RT95 and Anytone AT-778UV (they are both the same radio) is a simple & popular dual-band. Out of the box it has a fairly-limited frequency range, but the internet has since figured out how to unlock these radios for greater spectrum access. Like the Baofeng handhelds, they are not the most accurate or clearest radios in the world, but they get the job done in a pinch if you are looking for something to get started with.

• Another popular unlockable dual-band is the TYT TH-8600, and its sibling, the Rugged GMR25, which both support outright firmware swaps. They also have a quad-band cousin, the TYT TH-9800.

• BTECH (aka Baofeng) makes cheap vehicle dual-bands as well, such as the UV-25 series. Depending on the sub-model, it may have wide frequency range, and may even be a tri-band, so your best bet for these is to just compare the specs of whatever models are easily available at the time.

CB isn't as popular as it once was, but it still has some practical uses.

Citizen's Band (CB) Radio is an older two-way radio service, which operates on the high end of the HF band at 27 MHz, or 11 meter wavelength. Since the wavelength is longer in this part of the spectrum, it can travel further distances that normal walkie-talkies. This has made it the radio service of choice for long-distance truckers and off-roaders for generations, but lately there has been a shift over to GMRS.

In some places, CB radio is still the band of choice. For example, some logging trails in the Pacific Northwest are still marked at the entrances with the preferred CB channel everyone on that trail system should stay on. Many truck and desert drivers still swear by them as well. It really depends on where you are, but popularity of these types of radios is fading fast, and in some places it is such an undisciplined wasteland that it is referred to as “Children's Band”.

This isn't to say these types of radios are not useful, as they do have their tactical advantages over FRS/GMRS in many scenarios. CB radios can be made to transmit very long distances using Skywave - that is, bouncing the signal off the ionosphere to reach distant parts of the earth. There are also single side band CB radios, which let you transmit with far more power. While hardly anyone hangs out on the side channels, if you know another person with a SSB CB you can communicate across vast distances license-free. And, since CB radio is right next to the amateur radio 10 meter band (28-30 MHz), some 10 meter radios can be used on the CB band, and vice-versa. For a time, there was a whole international black market for hacked CB radios that could transmit off-band like this. Nowadays on some radios, it can be as simple as a firmware flash.

These radios come in both handheld and stationary forms, and just like with the aforementioned dual-band radios, you're gonna get better range on the mountable radios with the big external antennas.

A full list of CB frequencies can be found at RadioReference.

If you are in the US, amateur radio licenses give you access to these additional bands. Other countries have similar types of licenses.

This is where it gets serious. While you can freely listen to any radio frequency all you want without a license, you will need a license to transmit on most bands. There are some bands (like the aforementioned FRS, MURS & CB) that you can use without a license, but they are few and far between. Most licenses are only granted to government agencies and large businesses.

This is where amateur radio (also known as ham radio) comes in. These are parts of the spectrum set aside for civilians and hobbyists who are really serious about radio, where they can play around with advanced radios in a designated big kids sandbox. If you want consistently reliable radio communication, you want amateur. If you want Digital Mobile Radio (DMR), you want amateur. If you want to communicate across vast distances, you want amateur. If you want to get internet on a mountain deep in a national park or BLM land, you want amateur. If you want to do wild radio experiments, you want amateur.

There are over two dozen different amateur radio bands allocated in the US alone, not counting similar allocations in other countries. Any given amateur radio generally only has access to some of these bands. Some people amass giant radio collections, forever looking for the perfect setup that can cover all the bands. Some people only focus on one or two bands. If you start out with one of the aforementioned dual-band or tri-band radios, you will already have a foot in the door on the most common walkie-talkie bands for amateur license holders.

Getting a license in the US (which lasts 10 years) involves a 35 question test that will run you $50, and gets you access to some of the amateur bands. Two more levels of tests and fees gets you access to the rest of the bands, including the international ones. Other countries have similar types of policies.

Marine Radio is all over the place, depending on the type of radio and what part of the world you are in. One popular marine radio band is in the VHF spectrum, which you can access with dedicated marine VHF radios, or with the aforementioned dual-bands and amateur radios. Keep in mind, that Marine VHF Radio is structured a little different from other walkie-talkie channels, with different frequencies (usually) used between ships and the shore. Many of the marine VHF radios will be water-resistant/water-proof and have weather radio reception built in as well.

Some marine frequencies are in the HF range between CB and AM radio, and require radios that can work on those frequencies. Unless you plan on buying a boat or doing regular shipyard operations, you will not need a dedicated marine radio. Dual-bands, HF transceivers, and many amateur radio models, can communicate with various marine radio bands already.

Law enforcement and other government agencies use two-way radios as well. Some municipal departments use normal 450ish MHz UHF radios, but most operate in government-use-only parts of the spectrum (usually in the 800-900 MHz range) where consumer & business walkie-talkies cannot reach.

For what should be obvious reasons, you should not do things like use a hacked 33cm amateur radio to illegally broadcast on police frequencies. You can however, freely listen to some of what happens on these channels. Read the Police Scanners article for more information.

Many amateur radio communities are very hostile to newcomers. Some of them are also creepy as hell. This is one social sphere where it definitely helps to lurk moar before you open your mouth. By the time you get your license, you will ideally have lurked quite a bit. If not, keep lurking. Trust us.

Also, it generally helps to be polite. This goes beyond common-sense things like 'don't shout racial slurs at people,' or holding up a popular channel with long, nonsensical or annoying broadcasts. This also means using the same power levels as everyone else. This means not broadcasting digital data transmissions on channels where everyone else is using analog voice. While nothing is physically stopping you from being a dick and overloading some of these frequencies with whatever you want, the fact that most people do not is one of those things that separates us from the animals.

Most important of all, remember that nothing is secret on the radio. Anyone can listen in locally, and sometimes even across the world. Some places have receivers set up, whose sole purpose it is to pick up everything broadcast on popular comms channels, and livestream it over the internet (especially repeater frequencies). Various governments are also listening to these frequencies all the time, which is part of the reason that encryption is generally illegal to use on civilian bands. However, nothing is stopping you from doing things like employing code words or a quick morse signal to broadcast coded alerts. When you do have to transmit, transmit as little as possible, not only for security reasons but also because it is easier to repeat short messages if you have to. Get some practice using these radios as a group, using different communication methods in various settings (woods, city, desert, etc) before you use them during protests or live operations!