Walkie Talkies – The Old Ways To Communicate Can Still Be The Best

Without giving too much about this radio earpiece article, but I found it remarkable and related to what I’m now doing.

earpieceWalkie Talkies are portable communication devices consisting of low-level radio transmitters and receivers.

Walkie talkies are often pictured as that black bulgy transistor with a big antenna that one has to hold near his mouth before he speaks.
However, design and technology has really changed the look and feel of Walkie Talkies. In addition, they are just an amazing toy for kids, it lets them have a lot of fun while playing around and communicating at the same time.
Walkie Talkies – A Little History

The first walkie-talkies were developed for military use during World War II, and spread to public safety and eventually commercial and job site work after the war. Typical walkie-talkies resemble a telephone handset, possibly slightly larger but still a single unit, with an antenna sticking out of the top.
Early Handie-Talkies had tubes and ran on 4, 45-volt dry cells or 12V Nickel-Cadmium batteries. Surplus Motorola Handie Talkies found their way into the hands of ham radio operators immediately following World War II. Walkie-talkies are widely used in any setting where portable radio communications are necessary, including business, public safety, outdoor recreation, and the like, and devices are available at numerous price points.

Walkie-talkies, thanks to increasing use of miniaturized electronics, can be made very small, with some personal two-way UHF radio models being smaller than a pack of cigarettes (though VHF and HF units can be substantially larger due to the need for larger antennas and battery packs).

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

An unusual feature, common on children’s walkie-talkies but seldom available otherwise even on amateur models, is a “code key”, that is, a button allowing the operator to transmit Morse code or similar tones to another walkie-talkie operating on the same frequency.

Motorola
The first radio receiver/transmitter to be nick-named “Walkie-Talkie” was the backpacked Motorola SCR-300, created by an engineering team in 1940 at the Galvin Manufacturing Company (fore-runner of Motorola). Handie-Talkie became a trademark of Motorola, Inc.

The abbreviation HT, derived from Motorola’s “Handie Talkie” trademark, is commonly used to refer to portable hand held ham radios, with “walkie-talkie” used to designate more specialized commercial and personal radios. Motorola also produced the hand-held AM SCR-536 radio during World War II, and it was called the “Handie-Talkie” (HT).

Motorola’s public safety radios of the 1950s and 1960s, were loaned or donated to ham groups as part of the Civil Defence program. Motorola is forever introducing new models, so don’t get bogged down looking for any particular model, since the model numbers change frequently.

Today, GMRS radios such as Motorola’s T5950 can reach several miles.
Product
While FRS walkie-talkies are also sometimes used as toys because mass-production makes them low cost, they have proper super heterodyne receivers and are a useful communication tool for both business and personal use. Motorola has a huge chunk of the market and consistently receive high marks from consumer products testing groups.

Kids
Your kids will get as much of a kick out of it as we did as children. Another difference from cell phones is that there’s no air time charge (at all, ever), so you can give one to your kids without worrying. The kids loved having them around since it gives them more independence and freedom, especially on out door trips and camping.

Walkie Talkies are a fun way to communicate with your friends and is a pretty good deal considering how cheap they are. Whether you are on the slopes, hiking or simply mucking around in your own house or garden, Walkie Talkies are an absolute must.

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What is an Acoustic Transducer

When we found this article we were so excited, having hunted for over one year for this, discovering it on this website was an thrilling day for yours truly.
An acoustic transducer is an electrical device that coverts sound wave vibrations into mechanical or electrical energy. They have various practical applications, including sound recording and sound playback. A specialized model, called an ultrasonic acoustic transducer, can be used to measure distance to, as well as the mass of, an object.

Common types of acoustic transducers used in sound recording include microphones, earphones, and guitar pickups. These create electrical energy when moving parts inside the transducer, such as electrical plates or ribbons, are exposed to sound vibrations. The electrical energy produced inside the transducer is sent first to an amplifier.

The amplifier then sends this energy to its final destination, usually a loudspeaker or recording device. The loudspeaker reproduces the sound at a level that the human ear can hear. A recording device will retain the electrical signal information. The recorder will send the stored signal to a loudspeaker during playback.

An ultrasonic acoustic transducer can be used to measure distance or the mass of an object. The most common type is the piezoelectric acoustic transducer. These include a piezoelectric ceramic element that creates and distributes ultrasonic sound waves.

Sound waves travel to an object from a piezoelectric transducer through material called a couplant. The couplant is usually water. Sound waves bounce off the object and return to the transducer in the form of an echo. The time it takes for these echoes to return to the transducer is used to calculate the distance to the object.

Underwater sound navigation and ranging (SONAR) is a common use of an ultrasonic acoustic transducer. SONAR uses directional beams of sound waves. This enables the SONAR operator to determine the direction and distance to an object.

SONAR systems can be active or passive. An active system sends out sound waves and listens for echoes. A passive system listens for noises made by ships, fish, and landmasses.

An electromagnetic acoustic transducer (EMAT) is another form of ultrasonic transducer. Instead of a ceramic element, an electro magnet is the main component of an EMAT. This is a type of non-contact, or non-destructive transducer. Unlike piezoelectric transducers, EMATs do not need a couplant to carry sound waves. Instead, two electromagnetic fields are generated to disburse ultrasonic waves.

EMATs can easily be used almost anywhere since no liquid is needed. For example, EMATs can be used to check for flaws in underground pipes. A downside to EMATs, compared to piezoelectric transducers, is that EMATs create weaker sound fields.