Friday, February 27, 2015

Cambridge United v Manchester United: Sepura kit out U’s stewards with new radios in time for big match

SEPURA has kitted out Cambridge United stewards with radios ahead of tomorrow's big FA Cup with Manchester United.

The portable DMR radios replace the club's analogue communication system and will be officially used for the first time at the R Costings Abbey Stadium when Richard Money's side face the Red Devils in the sell-out fourth round fixture.

U's chief executive Jez George said: "The forthcoming FA Cup match is one of the biggest event in the history of our club, we are aware of the global exposure that it will give to Cambridge United and need to ensure that everything runs smoothly and successfully on the day.

"Thanks to our new Sepura digital radios we'll be ready to overcome any challenges that may arise during the event."

Read more: http://www.cambridge-news.co.uk/Cambridge-United-v-Manchester-United-Sepura-kit-U/story-25907956-detail/story.html#ixzz3Q7DHgeWn

Monday, February 23, 2015

What is an Acoustic Transducer?

From Wisegeek.com “What is an Acoustic Transducer?” (19 January 2013)

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.

Monday, February 16, 2015

Jawbone earpiece makes it easier to love smartphones

This is located over on this www.thestar.com, please enjoy

Jawbone began making it easier to love Siri, Google Now or other virtual assistants in a hint at the future portrayed in the Oscar-nominated filmHer.

The San Francisco-based company behind sophisticated and stylish wireless ear pieces released a new ERA model packing big technology in a diminutive form and enabling users to speak more naturally with software on their mobile devices.

"I hope they don't fall in love with their operating systems, but they will at least rekindle a relationship with voice commands," Jawbone audio product manager Gernard Feril said while providing AFP an early look at the new ERA.



Feril was making a playful reference to the Spike Jonze film Her starring Joaquin Phoenix, who plays a man who falls in love with a personal computer operating system.

Advanced Siri and Google Now software, which combine natural language exchanges with contextual awareness and even anticipating what users might want, have created a place for an ERA ear piece with enhanced technology for speaking to smartphones as one would a person, according to Feril.

Jawbone built in wide-band audio, high-quality microphones, and NoiseAssassinsoftware to block out unwanted sounds to make voice quality closer to what is found in Internet telephone calls than in typical ear pieces.

Being able to speak commands and have spoken exchanges with virtual assistants through the ear piece frees people to either ignore smartphone screens or use them for other tasks, such as e-mail, games or maps.

"This device has become so powerful," Feril said of the smartphone in his hand, "that holding it to your face limits what you're doing."

And, as screen sizes of mobile devices have grown, they become awkward to hold up to faces, he noted.



The annual Consumer Electronics Show gadget extravaganza that played out recently in Las Vegas was rife with headsets. Jawbone set out to distinguish itself with a tiny, high-quality ear piece crafted with style and brains to complement smartphone lifestyles.

Feril billed ERA as the smallest, lightest, best-sounding ear piece available.

ERA was priced at US$99 (RM300) at www.jawbone.com, but could be purchased with a protective charging case for US$130 (RM390) to increase talk time to 10 hours from four. The ear piece was less than half the size of its predecessor.

Since ERA is tiny, Jawbone added a "locator" feature that signals an ear piece to chirp to disclose where it is.A Jawbone "Nerd" USB device can be used to automatically synch the ear piece to laptop computers.

"It's the Internet-of-me," Feril said. "It is not about the things, it is about the person. You can see that, at least in Spike Jonze's interpretation, the Internet is going to be with you at all times."

Wednesday, February 4, 2015

How Many 2 way radios Can Run on one Channel?

Theoretically, you can use an unlimited amount of walkie-talkies on the same channel (although in practice you might experience a few problems if you took that suggestion literally). Basically, there isn'€™t really a set limit. You could use as many as you like provided they are set up correctly. Anybody set to the right channel and in range at the time of transmission would then be able to pick up the signal and respond to it.

Most radios have access to 8 channels. These channels each have 38 separate €˜identification tones€™. The user sets his/her channel up with the desired tone and then only other users who know the channel/tone will be able to hear the transmissions. As a result, there are, in any given area, about 304 different combinations, so signal interference is unlikely to affect you.

Please do not interpret this answer as saying that your radio has access to 304 possible channels. It does not. It will likely only have access to 8. Some less reputable manufacturers tend to falsely imply access to 304 channels; this is simply not the case. You will have access to 304 possible tone/channel combinations, that’s all.

To better explain the CTCSS codes and how they work; we'€™ll include a little information from Amherst.co.uk€™s FAQ page.

€œCTCSS stands for “Continuous Tone Coded Squelch System”. These codes are also often called “Privacy codes” If a CTCSS tone is selected; a CTCSS sub-audible tone is transmitted along with the regular voice audio by the transmitting radio. The receiving radio, set to the same CTCSS tone, will only receive audio if it contains that sub-tone. Interference from other users on the same frequency is therefore rejected (unless they are also on the same sub-tone). This is a way of allowing groups of users of walkie-talkies on the same channel to avoid hearing messages from other nearby users”.

So, in conclusion, you can probably use as many walkie-talkies as you like on the same channel. As long as the units in question are of the same type (either VHF or UHF) and have the same CTCSS setup, then you simply shouldn'€™t have a problem. You also shouldn'€™t suffer from signal interference due to other users (although you may still experience signal loss/interference/degradation from other sources). We have talked about combating signal loss elsewhere, so please see the other questions if you have any problems in this area.

SOURCES

http://www.amherst.co.uk/walkietalkie/walkie-talkie-radio-faq-basics.htm

http://www.homephonesonline.co.uk/information/qa-walkie-talkies.htm