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

NASA Confirms Liquid Water on Saturn’s Moonell

A major scientific discovery was made this week as scientists uncovered overwhelming evidence indicating the presence of a ‘great lake’ on Saturn’s moon Enceladus. The discovery is important because it marks Enceladus as being a possible site for life existing outside of our own planet.

Initially, icy material was seen being squirted into space from an odd ‘striped’ pattern on the moon’s southern pole. It was theorized that this material was water being ejected from a large body of liquid H20 on the moon’s surface. This week, measurements from NASA’s Cassini probe revealed the water’s gravitational signal, effectively confirming the theory. The Cassini probe even sampled the water as it was ejected into space.

Professor Luciano Less, of the Sapienza University of Rome, who was interviewed on the subject by BBC news, said, "The measurements that we have done are consistent with the existence of a large water reservoir about the size (volume) of Lake Superior in North America,"

To add context to this statement, Lake Superior is the largest freshwater lake in the world by surface and the third largest in the world by volume. It reaches depths of 147 metres and has an approximate volume of 12,000 Km3. It also plays home to over 80 different species of fish.

Data extracted from the probe suggests that the water is about 40km underneath Enceladus’ icy surface.

Enceladus is locked in an eccentric orbit around its parent planet; this means that the moon’s orbit is non-circular and it therefore follows that Saturn’s gravity will have the effect of melting the ice in some places and freezing any liquid found in others.

There are a lot of places in our solar system that possibly house liquid water, but not as many where that water can come into contact with rock. Rock is important because rocks release minerals and salts into the water - and these materials are among the key building blocks of life.

Professor Andrew Coates of the UCL-Mullard Space Science Laboratory was also interviewed for BBC news, he remained positive regarding the possibility of microbal life on Enceladus. Prof Coates said, "I think Enceladus has gone to the top of the charts in terms of a place where there could be life. (...) It's got several of the things which you need for life - there's certainly the presence of heat, there's liquid water in this ocean, there's organics and that type of chemistry going on. (...) The only question is, has there been enough time for life to develop?"

However, as Professor David Stevenson, from the California Institute of Technology, pointed out “we don’t know whether the ocean is beinghere or is freezing up”. It is theoretically possible that the great body of water confirmed this week has been there for 100 million years, but it is also potentially a far more recent development. At present, no one knows for sure.

you can obtain the original piece here

Utility safety: Headsets protect worker hearing and improve communication

This was originally posted on this website, credit should go them as this is a important article.

Work safety equipment: Motorola Solutions Inc. has announced the joint collaboration between 3M and Motorola on the 3M Peltor Heavy-Duty Headset Portfolio. Motorola is now the sole distributor of the MT7H79 Direct Radio Connect Headsets, optimized and certified to meet Motorola’s performance standards for APX and MOTOTRBO(TM) two-way radios. The initial launch will include 15 new headset products from the Peltor HT, MT and Tactical Pro Series that serve as complementary accessories to Motorola’s digital two-way radios. Ideal for noisy work environments, this portfolio will help customers meet hearing conservation program requirements. Hearing conservation programs are mandated by the U.S. Occupational Safety and Health Administration to protect workers with significant exposure to occupational noise from hearing impairment.

Since 2004, the U.S. Bureau of Labor Statistics (BLS) has reported that nearly 125,000 workers have suffered significant, permanent hearing loss. Hearing loss is the most commonly recorded occupational illness in manufacturing. These protective communication products provide hearing protection for noise levels above 82 decibels (db) while allowing users to hear their surrounding environment and communicate. The portfolio of solutions is ideal for manufacturing, public safety, public works and utility workers.

KEY FACTS

• The 3M Peltor heavy-duty headset portfolio comes in a variety of styles, providing flexibility and comfort for extended wear including over-the-head, neckband and hard-hat attached options.

• It also has a 22 â€" 26dB noise reduction rating that is key for hearing conservation.

• The portfolio includes field replaceable parts and repair service after the 12-month warranty period.

• The companies will continue to build-out a suite of unique protective communication headsets for Motorola two-way radios.



Doug Moses, 3M Marketing Manager, Protective Communications, said: “3M and Motorola Solutions are globally recognized solution providers, and 3M is excited to work closely with a company that offers premium products in the radio market. The 3M brand has been dedicated to providing hearing conservation solutions for noisy environments for years. Through this joint relationship, we are able to complement Motorola’s radio expertise for enhanced communication in high noise environments.”

Nick Candotti, director, Accessories & Energy Business, Motorola Solutions, said: “Motorola Solutions is pleased to collaborate with 3M Peltor to better equip workers and help improve their safety. This positive working relationship, in addition to the expanded two-way radio accessories portfolio, creates an extensive array of hearing protective communication solutions for our customers.”

What You Could Be Missing Out On When You Don't Look At The Icom IC-F4029SDR

Anyhow ladies and gentlemen, i’ve one more outstanding Radio piece of writing for you to read, i know, you do not need to thank me each and every one, just click a social like to the short article to demonstrate your appreciation.

Professional Digital Licence Free Transceiver

The IC-F4029SDR professional digital licence-free transceiver utilises the latest 6.25kHz ultra narrow digital voice technologies, providing digital clarity, razor sharp signalling performance and a level of secrecy from less congested dedicated digital PMR channels.

The IC-F4029SDR was recently featured on Channel 5's "The Gadget Show" winning a comparison test against another leading manufacturer.

DIGITAL PMR 446 FEATURES

The IC-4029SDR utilizes 4FSK/FDMA modulation and 6.25kHz digital narrow channel spacing, which is half the channel spacing of the existing analogue PMR 446 system. This way, the 100kHz band width allocated for digital PMR 446 is efficiently divided into 16 channels, or twice the current analogue voice channel capacity making this product incredibly spectrum efficient.

A Path from analogue PMR 446 to digital PMR 446 in one unit

By changing the channel setting, the IC-F4029SDR can be used on existing analogue PMR 446 channels. This provides users with an upgrade path from analogue PMR 446 to digital PMR 446 in one unit. Being analogue/digital compatible, any businesses or private users currently using analogue PMR446 can begin replacing their analogue radios with IC-F4029SDR and enjoy digital quality as well as relief from congested spectrum.

32-status messages

32 codes of prefixed status messages can be sent and received. 16-character messages and 6 types of alert beeps sound that for call reception, are programmable for each message.

“Common ID” group code

This function is similar to an analogue CTCSS/DTCS code. By setting 1â€"254 common ID codes, the IC-F4029SDR opens its squelch only when a matched code is received. It provides quiet stand-by and group call functions while sharing a channel with several groups. The code “255” is the fixed code for an all stations call.

Security of digital voice

‘Eavesdropping’ by current scanner receivers is impossible at this stage. Since there are no other competing radios, initial users will have a high level of security in digital voice communication mode.

Additional Digital Features

Group call functions (up to 254 digital codes available)

Programmable 32 status message of up to 16 characters each can be sent to individual or group member radios when in digital mode. This is configurable by a PC

In addition to Icom default channel settings, other channel zones are preprogrammed to have matched settings with Kenwood and Motorola PMR446 models currently on the market. These radios can be sold to match Motorola/Kenwood current analogue configuration reducing the necessity to reprogram radios for customer’s fleets consisting of non- Icom radios.

ANALOGUE PMR 446 FEATURES

"Smart-Ring" and "Ringer" function

The “Smart-Ring” function checks the availability of your group members within the operating range. The “Ringer” function is used for manually sending a ring tone instead of a voice call. 16 types of ringing tones are available.

Tone find function

The tone find function allows you to find a tone used in a channel to decode a tone.

Built-in CTCSS/DTCS

50 CTCSS tones and 84 DTCS tones provide quiet stand-by. DTCS inverse mode is also programmable.

Lithium-Ion battery pack and rapid charger as standard

The IC-F4029SDR series shares Lithium-Ion battery packs with the IC-F3062, IC-F3022, IC-F34G and IC-F15 series. The IC-F4029SDR series is supplied with the BP-231 1150mAh li-Ion battery pack (provides 9 hours* of operating time) and BC-160 desktop rapid charger as standard. An optional BP-232 larger capacity battery pack and BP-230 economical battery packs are also available. Lithium-Ion batteries provide larger capacity and a longer operating time than a Ni-Cd or Ni-MH battery pack and allow flexible charging without memory effect.

Small and lightweight body

The IC-F4029SDR has a fixed type antenna and weighs just 280g (including BP-231). It measures only 53 x 195 x 32.5mm including the antenna. The aluminium die-cast chassis and polycarbonate casing combination is designed for durability. A rugged dual-rail guide chassis securely locks the battery to the back of the radio.

Alphanumeric LCD

The IC-F4029SDR incorporates an 8-character 14 segment alphanumeric LCD. An automatic LCD backlight is employed for night-time operation.

IC-F4029SDR Additional Features

Shares the same battery packs and accessories as the IC-F15/F34 series

Power on password

2-step Power save function

A first in the market, professional digital licence free radio

A Path from analogue PMR 446 to digital PMR 446 in one unit

Fantastic audio quality

Useful communication tool for light commercial users (initial users can benefit from security of digital voice)

Compact, lightweight body

High capacity lithium-Ion battery pack and rapid charger as standard

8-character alphanumeric display

32-status messages for digital PMR 446

“Common ID” group code

Existing analogue PMR 446 channels available with CTCSS/DTCS tones

Optional headset provides hands-free operation

2 year warranty on transceiver, 1 year warranty on accessories.

What Is a Covert Earpiece?

I don't know if you came here because you read it on social media, twitter, facebook, google +, stumble upon or somewhere else. But thank you for coming and I trust you take pleasure in reading this as much as I did.

A covert earpiece is a miniature earpiece worn by an individual while being effectively hidden from plain view. It operates as a radio accessory in times when a user does not want other people to know she or he is communicating with others using radio earbuds. Also known as an invisible earpiece or a surveillance earpiece, a covert earpiece is often worn by government agents, corporate security personnel, undercover law enforcement officers and corporate as well as government spies.

covert earpiece

While many occupations require the use of a radio headset for communication, a covert earpiece is primarily used in instances where communication is of an extremely private and sensitive nature. This is common in cases of private security details and surveillance projects. Sometimes people also use a covert earpiece to defraud businesses and others. Examples of such instances would include someone using an invisible earpiece to cheat on an exam or to defraud a casino by receiving remote information while playing a game.

On-air television personalities may also use a covert earpiece, which is not distracting to viewers, but allows the person to hear relevant feedback from producers and engineers in order to make sure a taping or live appearance flows smoothly. Individuals may also wear a covert earpiece when making a public speech. By doing so, the speaker can receive important cues or changes in a speech without the audience even being aware that communication is taking place between someone located behind the scenes and the individual delivering the speech.

Some covert earpieces are accompanied by a discreet microphone, which enables two-way communication. These are commonly used by security forces with a need for such communication, particularly during surveillance operations. These types of accessories are not only convenient because they feature hands-free operation, but also because they allow undercover security forces to blend in with crowds without having to use a visible walkie-talkie system of communication.

A covert earpiece does not contain any visible wires and is designed to fit inside the ear without being noticeable to the general public. Some devices are even designed to fit on a pair of eyeglasses while amplifying sound inside a person’s ear. An inductive wire is sometimes worn around the person’s neck, but is covered by clothing so as not to be discovered by onlookers. This wire is not connected to the covert earpiece, but connects to a separate radio device that helps modulate sound.

Children’s Letters To Santa Have Their Own Sorting Office

With December in full swing and ‘the big day’ now less than a week away, you’ll be heartened to know that a) today’s tech-savvy, smartphone wielding children still write letters to Father Christmas in the traditional manner b) that real people actually read them and c) that the children can expect a genuine reply to their letters.



The sorting office, which deals exclusively with children’s letters to Santa, is located in Belfast and is listed on the official Royal Mail address finder as being staffed by 10,000 elves, 1,000 reindeer and about 100 snowmen. The areas industry is listed as including “sleigh pulling, toy making and list checking (twice)”.

According to The Telegraph’s Sarah Rainey, around 250,000 letters, addressed to ‘reindeerland’, pass through this highly specialised sorting office every year. Morag Turnbull, who works as the Operations Manager at the Royal Mail in Edinburgh, told The Telegraph that, “The effort the children go to in writing them is wonderful (...) They cut out pictures of toys, draw pictures for Santa, attach stickers, feathers and all sorts of inventive touches. We start getting them as early as August, and we reply to as many as we can before Christmas â€" but it’s a mad, mad job.”

The letters usually have to be examined by hand, as the Royal Mail sorting machines struggle with kid handwriting, coloured craft paper and glitter. In addition, occasional parcels of food (for Santa and Rudolph, you understand), can (and frequently do), crash the system.

Perhaps the nicest part of this particular story, however, is just what the kids are asking for. In addition to predicable demands for iPads, new bikes and Disney memorabilia, many British children are apparently very selfless in nature.

A small boy named Noah, for example, sent Santa a drawing for his troubles, before asking for new work shoes for his mother and some Lego for his brother, his own request (a DVD player) was listed last of all. Many kids also ask for presents for their pets or their teddy bears and even more request something nice for their brothers and sisters as well as themselves.

A particularly moving letter came from a girl named Casey, who asked Santa Claus to name a star in honour of her granddad, who apparently died in January this year. “Can you give him a big hug and a kiss from me?” She wrote, “I don’t get to see him anymore, but this way I will be able to see him in the sky every night.”

So, the next time you find yourself suffering a bout of the ‘holiday blues’, fretting over January’s credit card bill or getting exasperated by just how busy December can be, take a deep breath and think about that little sorting office in Belfast, a place where the magic of Christmas is still very much in evidence. Think on that and smile.

Thank you for reading, have a wonderful Christmas and a Happy New Year!