Walkie-talkie

A walkie-talkie, more formally known as a handheld transceiver (HT), is a hand-held, portable, two-way radio transceiver. Its development during the Second World War has been variously credited to Donald Hings, radio engineer Alfred J. Gross, Henryk Magnuski and engineering teams at Motorola. First used for infantry, similar designs were created for field artillery and tank units, and after the war, walkie-talkies spread to public safety and eventually commercial and jobsite work.^[1]

For the building in London, see The Walkie Talkie. For other uses, see Walkie-talkie (disambiguation).

Typical walkie-talkies resemble a telephone handset, with a speaker built into one end and a microphone in the other (in some devices the speaker also is used as the microphone) and an antenna mounted on the top of the unit. They are held up to the face to talk. A walkie-talkie is a half-duplex communication device. Multiple walkie-talkies use a single radio channel, and only one radio on the channel can transmit at a time, although any number can listen. The transceiver is normally in receive mode; when the user wants to talk they must press a "push-to-talk" (PTT) button that turns off the receiver and turns on the transmitter. Some cellular telephone networks offer a push-to-talk handset that allows walkie-talkie-like operation over the cellular network, without dialling a call each time. However, the cellphone provider must be accessible.

Some units have additional features such as sending calls, call reception with vibration alarm, keypad locking, and a stopwatch.^[2]^[3] Smaller walkie-talkies are also very popular among young children.

In line to the ITU Radio Regulations, article 1.73, a walkie-talkie is classified as radio station/land mobile station.

Wide-band receivers, often including functionality, for listening to non-amateur radio bands.

radio scanner

Multiple bands; while some operate only on specific bands such as or 70 cm, others support several UHF and VHF amateur allocations available to the user.

2 meters

Since amateur allocations usually are not channelized, the user can dial in any frequency desired in the authorized band (whereas commercial HTs usually only allow the user to tune the radio into a number of already programmed channels). This is known as "variable frequency operation (VFO) mode.

Multiple modulation schemes: a few amateur HTs may allow modulation modes other than FM, including , SSB, and CW,^[14]^[15] and digital modes such as radioteletype or PSK31. Some may have TNCs built in to support packet radio data transmission without additional hardware.

AM

Accessories[edit]

There are various types of accessories available for walkie-talkies such as rechargeable batteries, drop-in rechargers, multi-unit rechargers for charging as many as six units at a time, and an audio accessory jack that can be used for headsets or speaker microphones. Newer models allow the connection to wireless headsets via Bluetooth. Some models also came up with the wifi integration such as Motorola XIRP 8600i series.^[19]

Mobile radio telephone

MOTO Talk

Serval project

Signal Corps Radio

Survival radio

Tank phone

Vehicular communication systems

Onslow, David. . IntercomsOnline.com. Retrieved 2008-10-24.

"Two-Way Radio Success: How to Choose Two-Way Radios, Commercial Intercoms, and Other Wireless Communication Devices for Your Business"

Dunlap, Orrin E., Jr. Marconi: The man and his wireless. (Arno Press., New York: 1971)

Harlow, Alvin F., Old Waves and New Wires: The History of the Telegraph, Telephone, and Wireless. (Appleton-Century Co., New York: 1936)

Herrick, Clyde N., Radidselopments in Telecommunications 2nd Ed., (Prentice Hall Inc., New Jersey: 1977)

Martin, James. The Wired Society. (Prentice Hall Inc., New Jersey: 1978)

Silver, H. Ward. Two-Way Radios and Scanners for Dummies. (Wiley Publishing, Hoboken, NH, 2005, 978-0-7645-9582-0)