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.

Gross, a radio engineer and one of the developers of the Joan-Eleanor system, also worked on the early technology behind the walkie-talkie between 1938 and 1941, and is sometimes credited with inventing it.

The team consisted of Marion Bond, Lloyd Morris, Bill Vogel, Dan Noble, who conceived of the design using frequency modulation, and Henryk Magnuski, who was the principal RF engineer.

[9] The terms are often confused today, but the original walkie-talkie referred to the back mounted model, while the handie-talkie was the device which could be held entirely in the hand.

Surplus Motorola Handie-Talkies found their way into the hands of ham radio operators immediately following World War II.

Motorola's public safety radios of the 1950s and 1960s were loaned or donated to ham groups as part of the Civil Defense program.

Walkie-talkies are widely used in any setting where portable radio communications are necessary, including business, public safety, military, outdoor recreation, and the like, and devices are available at numerous price points from inexpensive analog units sold as toys up to ruggedized (i.e. waterproof or intrinsically safe) analog and digital units for use on boats or in heavy industry.

Consumer and commercial equipment differ in a number of ways; commercial gear is generally ruggedized, with metal cases, and often has only a few specific frequencies programmed into it (often, though not always, with a computer or other outside programming device; older units can simply swap crystals), since a given business or public safety agent must often abide by a specific frequency allocation.

Modern units such as the AN/PRC-148 Multiband Inter/Intra Team Radio (MBITR) can communicate on a variety of bands and modulation schemes and include encryption capabilities.

While FRS walkie-talkies are also sometimes used as toys because mass-production makes them low in cost, they have proper superheterodyne receivers and are a useful communication tool for both business and personal use.

In addition, CB walkie-talkies are available, but less popular due to the propagation characteristics of the 27 MHz band and the general bulkiness of the gear involved.

Personal walkie-talkies are generally designed to give easy access to all available channels (and, if supplied, squelch codes) within the device's specified allocation.

The spread-spectrum scheme used in eXRS radios allows up to 10 billion virtual "channels" and ensures private communications between two or more units.

Later toy walkie-talkies operated in the 49 MHz band, some with frequency modulation (FM), shared with cordless phones and baby monitors.

The lowest cost devices are very simple electronically (single-frequency, crystal-controlled, generally based on a simple discrete transistor circuit where "grown-up" walkie-talkies use chips), may employ superregenerative receivers, and may lack even a volume control, but they may nevertheless be elaborately decorated, often superficially resembling more "grown-up" radios such as FRS or public safety gear.

Generally the operator depresses the PTT button and taps out a message using a Morse Code crib sheet attached as a sticker to the radio.

In addition to land mobile use, waterproof walkie talkie designs are also used for marine VHF and aviation communications, especially on smaller boats and ultralight aircraft where mounting a fixed radio might be impractical or expensive.

They are also used in recreational UTVs to coordinate logistics, keep riders out of the dust and are usually connected to an intercom and headsets Intrinsically safe walkie-talkies are often required in heavy industrial settings where the radio may be used around flammable vapors.

Applications on the market that offer this walkie-talkie style interaction for audio include Hytera,[14] Voxer, Zello, Orion Labs, Motorola Wave, and HeyTell, among others.

[15] Other smartphone-based walkie-talkie products are made by companies like goTenna, Fantom Dynamics and BearTooth, and offer a radio interface.