Not exactly sure what a feature means? This page provides a plain-English explanation of common two way radio features and terminology.
Radios operating within the 900 Mhz frequency range communicate well both indoors and and outdoors. This is the same frequency range used by many cordless phones. The biggest positive about two way radios using 900 Mhz frequencies is that they can be used by both individuals and businesses without a license from the FCC.
Two way radios with the adjustable gain feature allow you to adjust the sensitivity of your microphone. This is useful along with hands-free operation because it helps minimize the possibility of unintended noises triggering a transmission, or enhances the ability to pick up quiet voices.
An alarm sounds to alert the user of a specific event.
An altimeter measures altitude of an object, usually to determine how high it is above sea level.
Radios with this feature play a tone whenever a button is pressed. This helps you to confirm that the button was actually pressed.
Radios with the audio accessory connector feature have a port that will allow you to connect external devices to your two way radio. The actual devices supported vary by model. Some of the most popular external accessories are microphones, speakers, and hands-free kits.
The auto channel change feature will change all radios within your group to a new channel. This helps avoid interference. In order to use the auto channel change feature, all members of your group must have radios supporting this feature.
The radio will automatically power off after a set period of inactivity.
Most two way radios have a digital LCD display that displays useful information, such as your current channel. Radios with this feature allow you to turn on a lighted display, to make information easier to read in darker environments.
A battery charger will re-charge two way radios that include rechargable batteries. If you plan to use your two way radio with any frequency, rechargable batteries are a good idea and will pay for themselves in the long run!
A battery meter will indicate the amount of charge remaining on the battery.
Two way radios with this feature generally have a "low power" mode that they will switch to automatically after being left unused for a certain amount of time. While in the "low power" mode, the drain on the battery is less than during normal operations.
Two way radios are mobile devices and were intended to move around with you. Because of this all radios operate on battery power. Most models will work with standard alkaline AA or AAA batteries. Several models include rechargable batteries. Rechargable batteries included with two way radios are usually either Nickel Cadmium (NiCd) or Nickel Metal Hydride (NiMH). NiMH rechargable batteries are usually considered superior to NiCd. NiMH batteries usually last longer and have no "memory effect". NiCd batteries do suffer from the "memory effect" and because of this it is recommended that you completely drain your NiCd batteries before you recharge them.
This radio supports a wireless bluetooth device, such as an audio headset.
Busy Channel Lockout prevents you from breaking in on a channel already in use. When BCL is activated, an the radio will not transmit and alert tone may sound when the PTT switch is pressed.
Call tones allow you to transmit a tone to other radios in your group to alert them that you want to talk. This is similar to a telephone's ringing to indicate that someone wants to talk to you. Many radios allow you to choose from several different call tones.
Call waiting works similar to what you are used to with regular telephones. You will receive a notification that someone is trying to reach you if you are already on a call. Some radios with this feature will provide the option of allowing you to immediately accept the new incoming call, or reject it and call back later.
Lets you know who is transmitting to you.
The unit features a built-in camera.
Channel Announcement audibly voices the channel number/description. This allows the user to change channels without looking at the channel knob.
The channel scan feature enables a two way radio to continuously scan each channel for activity. When activity is detected on a channel the scan process will stop and you will hear the transmission.
A channel is a frequency on which two way radio users can communicate. There are 14 FRS channels and 15 GMRS channels, and of those 7 are shared. Radios supporting both FRS and GMRS will support 22 channels. To communicate with others using a two way radio, all radios in the group must be set to the same channel.
Two way radios with a clock will display the current time. Some radios with this feature also have an alarm feature.
Two way radios that are cloning capable can have their configuration easily loaded from a different radio. This makes setup a breeze when your business has quite a few radios. Cloning helps when you have purchased lots of radios, when you are adding new radios, or when you make changes to your configuration. Many radios that support this feature require that you also have a separate accessory to connect the radios together. This cloning support is often built-in to multi unit charging stations.
A sophisticated digital voice compression technology that reduces the static hiss between words. This technology extends the effective range of the radio and delivers noticeably clearer transmission quality.
Provides you with a "phone book" of contacts. You can use this contact list to easily select a channel for a group or individual (for radios supporting direct call).
Scans for the CTCSS tone used by other radios.
A digital compass will tell you which direction you are headed. Two way radios with this feature will usually show you abbreviations for your direction while the compass is active. Common abbreviations are: N, E, S, W, NE, NW, SE, SW.
A vocoder is a voice encoder and decoder. It converts analog speech into a digital signal and converts it back to analog.
The radio can operate in both analog and digital mode.
The direct call feature allows you to make a private call to a single radio within a group. Other radios within the group will not hear the conversation. In order to use the direct call feature, all members of your group must have radios supporting this feature.
Some radios supporting this feature, such as the higher end Midland radios, only support sending a call tone directly to a different radio within the group, not voice calling.
Acronym for Digital Mobile Radio. It is an open digital standard used by many digital radio manufacturers.
Two way radios that are drop-in charge capable are compatible with desktop type cradle chargers. In these chargers, you drop the entire radio in a cradle while it recharges.
Dual channel watch allows you to monitor two channel/privacy code combinations at once.
The eavesdrop reducer feature will allow you to set a special "eavesdrop reducer" code. Setting this code will cause your radio to garble the tranmission for anyone else who may be listening. Another radio with this feature must be set to the same "eavesdrop reducer" code before they will be able to hear your transmission correctly. This feature does not guarantee secrecy, but it does add an extra layer of privacy.
Radios supporting Emergency Alert have a button that, when pressed, will send out a distress call. Other radios within range will alert with the distress call. After sending the distress signal, the transmitting radio will also typically transmit in hands-free mode for a number of seconds.
If the radio receives call or text and the user does not respond, the radio emits an alert that becomes louder until the user responds.
Fixed antennas are not able to be removed from the radio.
Radios with a built-in flashlight are a good choice for emergency preparedness kits, for those that would be using a radio during an emergency situation where there may be a power outage, or for those that will simply be using the radio at night.
The radio can float in water.
Scans for the frequencies being used by other radios.
Frequency-hopping technology provides enhanced privacy. Radios supporting this feature do not communicate on a single frequency, like standard UHF/VHF radios. Frequency hopping radios will constantly switch frequencies, staying in sync with other radios in your group. This makes it almost impossible for your conversations to be overheard by individuals using other types of radios or scanners.
Built in front mount speaker.
FRS channels are channels that were set aside by the FCC for use by the Family Radio Service (FRS). There are 14 FRS channels available. The FCC has limited the amount of power that a device can use to broadcase on an FRS channel to .5 watts, which is a maximum of around 2 miles.
GMRS channels are channels set aside by the FCC for use by the General Mobile Radio Service (GMRS). There are 15 GMRS channels available. The range limit put in place by the FCC for FRS frequencies does not exist for GMRS frequencies. Because of this most radios that support the GMRS frequencies have a greater maximum range than FRS radios. The FCC requires that all operators using the GMRS frequencies obtain a radio license before operating their equipment. To obtain this license request form 605, which includes all forms and instructions.
GPS position data can be transmitted to or from other radios and/or dispatch stations.
Two way radios supporting interchageable face plates have snap-off front covers. These "face plates" can be replaced with others to give your radio a fresh look and style!
Intrinsically safe (IS) is a protection technique for safe operation of electronic equipment in explosive atmospheres. The concept was developed for safe operation of process control instrumentation in hazardous areas. Intrinsically safe devices limit energy which prevent fires & explosions from occurring in areas with hazardous chemicals, gases or other ignitable atmospheres.
Radios with the keypad lock feature allow you to "Lock" the buttons so that pressing them has no effect. This is useful if you are carrying the radio in your pocket or in a purse where buttons could accidentally get pressed.
Products that are lead free have been certified to contain no lead. Lead free products are generally considered safer to handle and more environmentally friendly.
The radio has an LED indicator that lights and/or changes color to indicate the receive, transmit, standby or other status of the radio.
The keys light up for use in low light conditions.
Lone Worker Mode will emit an audible alarm for a number of seconds at preset intervals when the Lone Worker Time has expired. If the user does not reset the timer by pressing the button or switch, the radio switches to Emergency Mode.
Two way radios with the low battery alert feature will alert you in some way when the battery charge is getting low. Some models will provide an audible tone to indicate the battery is low. Other models show a special icon in the display when the battery charge is getting low.
Radios supporting the manager lockout feature can have certain features locked, preventing access by the normal user of the radio. This can be used to keep everyone on the same channel and privacy code.
This is the warranty provided by the manufacturer. See manual for specific details.
MDC (Motorola Data Communications) signaling offers selective calling and ANI features.
Device accepts a memory card.
Two way radios with memory locations allow you to store your frequently used channel/privacy code combinations for easy access later.
The radio meets one or more military specifications, which should be listed beside the feature. This can include, but isn't limited to, standards for temperature, vibration, acceleration, shock, and water resistancy. Each different military specification have different standards associated with them, and they should be listed for the radio.
If you have missed a transmission, radios supporting this feature will alert you to let you know you've missed a call.
Mobile radios are known as vehicle-mounted: a transmitter-receiver (transceiver) used for radio communications from a vehicle. Mobile radios are mounted to a motor vehicle usually with the microphone and control panel in reach of the driver. In the US, such a device is typically powered by the host vehicle's 12 volt electrical system. Mobile radios can be found in police, fire and highway patrol vehicles and on construction sites.
This feature allows you to check if a channel is clear before you transmit.
Radios that support NOAA weather alerts will pro-actively alert you when a weather alert, such as a severe weather warning, is issued in your area. This means that if you are concerned about possible severe weather, you don't have to continually monitor a weather channel. Instead you can rest assured that your radio will alert you when an alert is issued. NOTE: Weather alerts are not yet supported by all NOAA stations.
The noise filtering feature reduces unwanted noise. Many models accomplish this by shutting off weak transmissions, thus eliminating unwanted noise due to terrain and conditions. For some other manufacturers, turning this feature on means that the radio only receives transmissions from other radios by the same manufacturer with this feature enabled.
NXDN™ is a Common Air Interface (CAI)based protocol used by digital mobile radios.
Expansion slot for an additional board (Such as adding voice scrambling).
The Out-of Range alert feature lets you know when two such radios are within range. When the Out-of-Range feature is active, your radio will automatically transmit a code at specific intervals in an attempt to handshake with the other radio. If the code is received, the other radio will send a confirmation code.
Project 25 (P25) is a standard for the manufacture of digital 2-way wireless communications devices that are interoperable. P25 was created by and for professionals in public safety is and managed by the Telecommunications Industry Association (TIA Mobile and Personal Private Radio Standards Committee TR-8). To comply with P25 standards, radio equipment must meet a minimum set of requirements to be interoperable with other P25 devices. This allows users of different systems to contact one another directly via radio for public safety communications.
PC configurable radios can be connected to a computer and configured through a dealer or manufacturer provided software application. These applications usually provide a user friendly way to adjust radio settings, or change user selectable frequencies.
Two way radios that are plug-in charge capable have a port where you can plug in a charger. This is similar to how most wireless phones are charged.
The power selectable feature allows you to switch between high and low power modes for GMRS frequencies. Low power mode would reduce the range of your two way radio. If your group is using a GMRS frequency, it could be useful to have to option to reduce your range if you are receiving unwanted transmissions from outside of your group.
The radio requires a password when powered on to prevent unauthorized users from access.
The radio allows you to set a preferred frequency when scanning.
Many radios divide individual channels up into a certain number of privacy codes. Instead of only needing to be on the same channel to communicate with other members of your group, radios using privacy codes require all radios to have the same channel/privacy code combination in order to be able to communicate. This is an extremely useful feature. In places where many people are using two way radios, such as sporting events or theme parks, it would be very difficult to find a channel that wasn't always being used or monitored if only 22 channels were available. Privacy codes make it possible for your to take your two way radio to high traffic places and still be able to communicate with your group in relative privacy.
A programmable button is a button on the radio that you can program or assign to perform a user specific function.
LED alert indicator is user programmable.
It is important to be aware that the number of miles of range advertised by two way radio manufactures is always the maximum range that the radio will get under perfect circumstances. Many things can affect the range, such as trees, bushes, buildings, vehicles, or almost anything that could interfere with line of sight.
This is the opposite of the Noise Filter feature. When the range extender feature is turned on, your radio will receive even very weak transmissions. This may result in unwanted noise, but will extend the range of your two way radio.
Some two way radios include rechargeable batteries. If you plan to use your radio frequently, upgrading to a model that includes rechargeable batteries will pay for itself in no time!
A repeater capable radio has the ability to have the transmit (TX) and receive (RX) frequencies for a single channel set to different values. This allows the radio to communicate through a repeater - a device that amplifies a radio signal, greatly increasing range.
This feature allows you to reset the radio to its original factory settings.
You can playback the last 20 seconds, transmit saved messages, and record messages to yourself.
A ring tone is a tone or series of tones played to signal an incoming call.
S.A.M.E. technology allows for specific alerts to be sent as coded messages as part of a NOAA broadcast. A weather radio that is capable of decoding SAME messages can proactively alert to specific severe weather or civil emergency situations. A location is also coded into the message, allowing SAME capable weather radios to filter out warnings that do not apply to the owner's general area.
The following are just a few of the 60+ possible emergency announcements: tornado alert, child abduction, immediate evacuation, hazardous material warning, local area emergency, biological hazard warning, civil emergency, contagious disease warning, food contamination warning, power plant warning, industrial fire warning.
Radios with this feature allow you to remove a specific channel from a scan. This can be very useful if you need to perform a scan, but there are channels with activity that you know you are not interested in.
There are seven channels assigned by the FCC to the Family Radio Service (FRS) and General Mobile Radio Service (GMRS) that overlap. Channels 1 through 7 have been assigned to both services. Almost all radios that support the GMRS channels also support the FRS channels. You will sometime see a difference between how some radios supporting both services handle these frequencies. Some treat them as low range FRS channels and others as high range GMRS channels. Some others give you the option of setting the range yourself for these shared channels.
A signal strength indicator will give you an indication of how strong the signal of your incoming and outgoing transmissions are.
In silent mode, the radio will indicate an incoming transmission without making an audible alert of any kind. Typically, the display will flash several times to indicate the incoming transmission. This is a great feature for hunters, where a noise may be disruptive.
Some two way radios have a stopwatch feature. A stopwatch displays the amount of time between when it was started and when it was stopped.
Stun and Kill disables a radio over the air and Revive restores the disabled radio.
Radio is submersible to JIS7 standards. Radio is waterproof to 3.3 ft (1 m) of water for 30 minutes.
The talk around function sets the transmit and receive frequencies to the same frequency for communicating transceiver-to-transceiver.
The Talk Confirmation Tone is sometimes called a "Roger Beep". When this feature is activated, a tone is transmitted to the listener after a transmission. This alerts the listener that you are finished, and that it is their turn to talk.
TDMA (Time Division Multiple Access) protocol divides a digital signal to allow multiple users to share the same frequency. TDMA offers power and spectrum efficiency at low cost.
Allows you to send SMS text messages to other people in the group.
The timeout timer feature is intended to prevent accidental transmissions and to save battery life. If the "TALK" button is held for a long period of time, the radio will automatically stop transmitting.
Transmit Inhibit disables transmitter from use.
The transmit power of a two way radio is measured in watts and is the major factor in determining the range of a radio. Generally the more watts of transmit power, the greater the range of the radio. The FCC limits the transmit power of radios on the FRS channels to .5 watts.
Trunking is system that uses a pool of frequencies to share a minimum number of channels between a large number of users. Trunking is commonly used for two-way radio communications by government agencies, municipalities and emergency response services who share the same frequency spectrum. Users are assigned to "talkgroups" instead of individual frequencies. Trunking allows the available channels and bandwidth to be managed more effectively.
Two-tone and Five-tone codes can be decoded on a channel.
Two way radios supporting UHF frequencies will operate on frequencies in the 450 Mhz - 470 Mhz range. UHF radios are more popular than VHF because they offer better range inside steel or concrete structures.
Radios with a USB port can be charged using a standard USB cable. These cables are extremely common. Chances are you already have one for your cell phone, iPod, MP3 player, or other small electronic device. USB cables are widely available to connect to a PC, or to plug into a AC wall or DC vehicle port.
Two way radios with user selectable frequencies separate the concept of channels from frequencies, and allow the user to assign a channel number to a frequency from a built-in list. For example, a two channel business radio may support 56 frequencies. The user could go into a simple "programming mode" and assign channel 1 to any of the supported frequencies. This differs from a "dealer programmable" radio, which typically could be set to a relatively limitless number of fequencies but would be unchangeable by the end user.
Two way radios supporting VHF frequencies will typically operate on frequencies in the 148 Mhz - 174 Mhz range. VHF radios work best when used outdoors or in and around wood structures.
Two way radios with the vibrate alert feature have the ability to vibrate to alert you that you are receiving a message. This is very useful in noisy environments where it would be difficult to hear a call tone or a message.
Your radio actually talks to you in a humnan-like voice. You will hear the prompt spoken in plain English.
The radio is capable of recording an incoming message for a specified period of time when activated.
The voice scrambling feature garble your transmissions, allowing you to have conversations that are more private and secure. In order to use the voice scramble feature, all members of your group must have radios supporting this feature. This feature does not guarantee secrecy, as someone with a similar radio could hear your conversations, but it does add an extra layer of privacy.
The voting mode scanning detects the signal strength level of repeater stations and automatically selects the strongest station, useful for roaming between 2 or more repeater sites. Once you program the voting mode to a memory zone, you can easily start voting mode operation by changing the zone setting.
Radios supporting the Voice Activated Transmit (VOX) feature allow you to use your two way radio "hands-free". The radio will automatically begin transmitting when you speak.
Water resistant two way radios are better suited for use in environments where they may get wet.
Radios supporting this feature can tune into broadcasts by the NOAA Weather Radio and Environment Canada Weather Radio. Most radios that will allow you to listen to weather channels also have the ability to alert you automatically to emergency weather broadcasts. This feature requires that NOAA or Environment Canada service be available in your area. Check with your local weather office to verify that this service is available.
The weather scan feature automatically scans all NOAA channels on a weather radios and stops on an active channel. When the channel is inactive for ten seconds, the radio will continue to scan.