Archive for May, 2016

The Original Two-Way Radio: The Tin Can Telephone

The most intricate and revolutionary advances in modern technology have had their origins in some of the most rudimentary sources. The two-way radio has become a bellwether of 21st century cutting-edge technology, but what’s now state-of-the-art still has the same fundamental intent as a homemade “toy” many of us played with as kids: the tin can telephone. And while we’re on the topic of radio nostalgia, we invite you to get a bigger-picture view of the cultural impact of the radio. Now that we’re ready to move on, here’s what you should know about the tin can telephone:

History in the Making

Before they were introduced to smart phones, cell phones and wireless technology, kids derived a unique fascination from the tin can telephone. All it took was two tin cans – or paper cups – with the tops removed, duct tape, string, a hammer and nail and any decorative embellishments one wanted to add to create this oh-so-basic version of a two-way radio.

Tin Can Telephone Schematics: How it All Worked

The process of making a tin can telephone would start by turning either cans or cups upside down and hammering a nail through the bottom of each can to make a hole in the center. Then you’d cut a length of string anywhere from 5 to 15 feet long and poke one end through the bottom of one can, knotting on the inside. After doing the same with the other end of the string in the opposite can, you and the person on the other end of the line would each take a can and move apart until the string is taut. When one of you put a can up to your ear, the other would talk directly into the other can, with the sound of the voice being transmitted across the string.

When we speak, our voices create vibrations, which travel down the string, if it is stretched tight enough, and vibrate the bottom of the can on the other end. That then vibrates the air, and those vibrations get transmitted to the other person’s ear.

While this was a common children’s activity in the 20th century, the tin can telephone actually predates the electromagnetic phone. The tin can telephone has also been called the “lovers’ telephone,” and it evolved from experiments conducted by Robert Hooke, an English inventor and physicist in the 1600s.

1 comment May 19th, 2016

The Wireless Technology that Enhances Firefighter Safety

Firefighters are some of America’s bravest life-savers. Keeping these heroes safe has taken an important step forward with the advance of wireless communications technology.

How Firefighters Use Wireless Communication

Many fire departments have upgraded their equipment over the past couple of decades to now include wired headset and intercom communication systems. Wired intercom systems that employ noise attenuating headsets have moved communications into the 21st century for firefighters on their way to a blaze or on the scene of an emergency. Now, wireless headset communications have made their way into the arsenal of many fire departments.

Wireless systems free firefighters from the physical connection to equipment and apparatus as is the case with wired communication systems. Without cumbersome wires limiting their movement on an emergency scene, firefighters are safer and more able to respond to incidents and rescue victims. The can also speak without shouting over the attendant noise of an emergency incident when using wireless communication technology, which has also proven to have benefits in aerial applications where bucket crews can communicate freely while operating the bucket in midair.

Two-Way Radios for Firefighters

Two-way radios and their wireless accessories, including headsets and microphones, help firefighters confront emergencies safely and with greater mobility and efficiency. Some of the features of these wireless systems more fire departments have adopted include large, recessed Push-to-Talk (PTT) and emergency buttons that are easy to access and also made to prevent inadvertent activation by a firefighter wearing bulky equipment, outdoor GPS availability, volume control and a task light.

Fire companies considering an upgrade to wireless communications should consider whether the system uses hands-free, full-duplex intercom technology; if the system will be compatible and interface with most HF, VHF and UHF radios; whether firefighters will be comfortable wearing the headsets over a long period of time; and whether the system’s components are durable enough to withstand the challenging conditions that emergency personnel will encounter on a call.

Add comment May 16th, 2016

Everything You Need to Know About Listening Technologies

TechWholesale has a wide range of products by Listen-Technologies that incorporate some of the most up to date audio technology for a listening experience that you will find virtually unmatched.

The Listening-Technologies Lineup

The Listen-Technologies LA-278 Behind-the-Head Microphone is secured over the speaker’s ears and wraps around the back of the neck. The LA-278 boasts exceptional audio clarity, with its ability to cancel out ambient noise, as well as superior comfort for the user and the capacity to be used for a long-term session. A radio frequency system made for conducting tours of up to 15 people, the Listen-Technologies LS-07-072 15-Person Portable RF System is 72 MHz and made to ensure that listeners can hear every word clearly either indoors or outdoors for auditory assistance and language interpretation on tours.

Other Must-Have Two-Way Accessories from the Brand

The Listen-Technologies LA-164 Ear Speaker with strong volume output and an antenna built into the cord of the headphone fits easily over your ear, is easy to keep clean and includes a clean earpiece that is reusable and which can be used with hearing aids. The Listen-Technologies LA-311-01 16-Unit Portable RF Product Charging/Carrying Case with sturdy construction and a shoulder strap for easy transportation is designed to store and charge up to 16 portable Listen RF products. Drop the units in the Portable RF Product Charging/Carrying Case and relax, because as soon as they have reached a full charge, they will shut off by themselves.

Add comment May 12th, 2016

Guide to Programming Your Two-Way Radio

A two-way radio is an ideal way to communicate with a handheld device in large, noisy or crowded areas where parties that need to stay in touch are not physically close to one another. In order to do so, though, you’ll need to figure out how to program your two-way radio first. Programming a two-way radio requires a few steps and a little bit of patience, but the end result will be well worth your while.

How to Program Your Two-Way Radio

Please note that two-way radio models vary, so you may need to adjust your steps in accordance with the brand/model you have.

With that out of the way, start by making sure that the radio’s battery is fully charged before programming the radio. After the battery has a full charge, you’re ready to start programming. First, set the default channel frequency. With the radio turned off, hold down the “Menu” key, then turn the radio on and release the “Menu” key after just one second. Select a channel using the arrow keys and, again, press the “Menu” button. Use the arrow keys to select a frequency within the channel you have chosen. Go through the same process again for as many channels that you wish to program. Press “PTT,” “Mon” or “Cal” to exit.

A zone is comprised of 16 channels, and your radio offers eight zones from which to select. Specify the zone of channels you want to look for. Press the “Menu” button, then the “Up” or “Down” button without stopping until the word “Zone” shows up on the display. Press “Menu” again to select the “Zone” function. Highlight the desired zone using “up” or “down” keys, then push “Menu” to select it. Choose the same zone as the people with whom you are trying to contact. Choose a channel within the specified zone and turn the “Channel Selector” knob to explore the different channels. The radio will scan and connect to compatible frequencies in range of the radio.

Add comment May 9th, 2016

What is Wireless Cloning and Why is it Used?

Are you at risk of being cloned? No, we’re not referring to the act of another version of “you” being created in some test tube, but rather the practice of wireless phone cloning, which only became a widespread issue over the last couple of decades.

A Primmer on Wireless Cloning

Copying the identity of one mobile telephone to another is called “cloning.” The most common purpose of cloning, which is really a form of identity theft, is so someone can place calls under the name (and on the billing account) of the actual subscriber. Coning has been a common practice with individuals with friends and family who live far away. Through cloning, they could phone home across oceans and continents and save on very expensive calls.

“Bag” phones – personal transportable cell phones made and used in the 1990s – brought about more widespread incidents of cloning, which increased with the advent of “brick” phones later in that decade. The act of cloning involved the perpetrator modifying or replacing the EPROM in the phone with a new chip. The phone’s electronic serial numbers (ESN) would be reconfigured via software and both it and the Mobile Identification Number (MIN) would be reprogrammed into a computer chip of another wireless phone. The phone calls made by the cloned phone are listed on the monthly bill of the person whose phone was cloned. The ESN-MIN could be captured over the airwaves and then cloned. The ESN-The carriers have developed authentication features that have greatly reduced cell phone cloning.

It’s not Sci-Fi; It’s Reality

Of the three types of fraud risks – cloning, theft and subscription fraud – incidences of cloning have actually fallen off quite a bit in recent years, although the other fraud risks have remained high. Not all cloned phones are created for illicit use, however. Some companies provide their employees with wireless phones that are intended strictly for business use. In order to keep their employees from using the phone for personal use, businesses mandate that their employees travel and work with two phones, without regard to how cumbersome that can be. Also, there are Third World nations served by networks operating in limited geographic areas, so the demand in these areas for a single Mobile ID Number can be high.

Add comment May 2nd, 2016