Learning The Essentials of a 2 way Radio Antenna

An antenna is essentially the most crucial element of a two way radio and other transmitting application such as cell phones, television, radar, or satellite communication. It is responsible for performing the most important task – converting electric power to transmittable radio waves and the other way round.

How an Antenna Works

To transmit a signal, the transmitter provides an electric charge that oscillates at a specific radio frequency to the terminals of the antenna. Consequently, the antenna sends out corresponding electromagnetic waves. During reception, the antenna takes some of the power of the transmitted electromagnetic waves to generate an extremely small voltage for the terminals, which is then redirected to a receiver that amplifies the signals. This is basically how an antenna works.

Extensive Applications

The applications supported by an antenna go beyond communication. The same concept powers today’s high tech wireless applications that run computer networks; Bluetooth enabled systems, garage door openers, and baby monitors. It’s important to know that a perfectly functioning antenna is not only critical to the functioning of your two way radio; it also helps maintain the life or longevity of your equipment.

The Bigger, The Better

The first and most important rule of thumb about an antenna to keep in mind is that the taller it is, the higher your db gain. A high volume of db gain is critical to achieving a stronger reach and better performance of your two way radio equipment. This basically translates to, “the bigger, the better.” However, in order to achieve results in practical situations, the antenna can have only so much height. In essence you have to sacrifice convenience for performance or vice versa. You can’t walk around or even install a gigantic antenna for all your needs, say for example your car radio.

Positioning of Antenna

The second rule of thumb pertains to the positioning of your antenna. The most optimal position for then antenna would be the centre of your metal car roof. In situations where this is not possible, you would need a “no ground plane” antenna. A no ground plane is basically just a metal surface that goes around the base of your antenna so that you have something for the radiating signal to react with. The next aspect you need to consider for your antenna is the frequencies at which you would be transmitting on. A VHF radio transmits and receives in a range from 136 to 174 MHz.

Chubby and Long Antennas

There are different kinds of two radio antennas available depending on how you want to use it. The large stock antenna is powerful and can be replaced or upgraded as you require. The shorter or stubby antenna provides a great deal of convenience. You can add a longer whip antenna to enhance your range. When it comes to two way radios, you stand to gain a great deal of advantages by having a business radio that comes with a removable antenna. The one problem is that removable antennas may not necessarily be compatible with all kinds of radios.

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Can you hear radio broadcasts through your teeth?

Do you mean me specifically? If so, then the answer is ‘no’ I’m afraid. I must also say that given the state of pop music these days, I’m actually very glad of it!

So…Awkward question time: are you hearing radio broadcasts through your teeth mate?

Lol. Just kidding.

Whilst it sounds like utter nonsense, there have actually been quite a few reported cases of people ‘picking up’ radio broadcasts through their fillings/dental caps over the years.

Our oft-quoted friend Cecil Adams, of The Straight Dope.com, actually answered this question back in 1992. In his answer, Adams highlighted two particularly interesting case studies. I’ll reprint them here, along with a link to the site in question.

Case #1. George, of suburban Chicago, lost a front tooth at the age of 12. A year or so later, in about 1961, he was fitted with a cap that was attached to the tooth stump with what George recalls as a brass wire. Thereafter he began hearing music in his head, generally popular tunes of the day, usually while he was outdoors. The music was soft but distinct. He never heard an announcer’s voice or commercials and was unable to identify what radio station, if any, he was hearing. After a year or two of this a new dentist put in a cap without a wire and the tunes stopped.

Case #2. Lois, also of suburban Chicago, says it happened just once, in 1947, while she was riding a train from her home in Cleveland to college in Rhode Island at about age 18. The experience lasted maybe 10 minutes. She couldn’t tell what station she was listening to but recalls hearing commercials and an announcer’s voice. She has silver tooth fillings but doesn’t recall if she’d had one put in just before the event.

Actress Lucille Ball even claimed to have helped the allies by intercepting radio signals in this, frankly rather bizarre, way. This story is widely re-told and was even used as part of the plot of the musical ‘Something For The Boys’.

Adams goes on to mention a piece on Snopes.com about the incident, which appears to feature the testimony of the actress herself, who says,

“One night I came into the valley over Coldwater Canyon, and I heard music. I reached down to turn the radio off, and it wasn’t on. The music kept getting louder and louder and then I realized it was coming from my mouth. My mouth was humming and thumping with the drumbeat and I thought I was losing my mind”

According to the Snopes account, after she related this strange story to Buster Keaton, he told her that it had happened to a friend of his.

If you’re interested, here’s Lucille’s account of ‘catching’ the Japanese spies, which allegedly transpired about a week later.

“All of a sudden, my mouth started jumping. It wasn’t music this time, it was Morse code. It started softly and then DE-DE-DE-DE DE-DE-DE-DE! As soon as it started fading, I stopped the car and then started backing up until it was coming in at full strength. DE-DE-DE-DE DE-DE-DE-DE! I tell you, I got the hell out of there real quick. The next day, I told the MGM security office about it, and they called the FBI or something and sure enough, they found an underground Japanese radio station. It was somebody’s gardener, but sure enough, they were spies”

As entertaining as Lucille’s story is, Snopes could find no record of the event, which surely would have been heavily featured in the local, if not the national, news. A cover-up to prevent mass panic? Personally, I don’t think so, as Snopes goes on to mention a Japanese submarine being spotted off the coast of Santa Barbara on February 23rd 1942, which was obviously an extensively covered event.

A discussion on Skeptics Stack Exchange.com uncovers another major flaw in this story (and all others like it). The users suggest (rightly) that any radio signal must first be demodulated in order to make any sense at all. As far as I know, dental fillings have no demodulation circuits.

So, is it possible or not?

Probably not. A demodulation circuit is not and has never been a part of a dental filling’s mix-up.

There is some compelling ‘evidence’ out there, as well as a couple of cases that have been looked into somewhat scientifically and featured in various respected journals, but then again, according to certain statistics, 3.7 million Americans have been abducted by aliens. That alarming statistic, in and of itself, ought to be enough to make you skeptical of anything.

Bone conduction headphones let me ditch the boombox, but still cycle safe

Long bike rides are an easy way to burn calories without terrorizing your knees, but it helps to have some tunes to keep things fun. My rides usually take me through bustling urban streets and isolated stretches of waterfront, so pumping out a soundtrack using a Bluetooth speaker is usually a viable option — mostly, anyway. Unfortunately, the wind-dampened output is never ideal and a high audio volume can burn through battery life, and bringing a backup device adds weight. Luckily, the ideal solution recently crossed my desk: AfterShokz’s Bluez 2S bone-conduction headphones.

If you’re not familiar, this style of device delivers audio as sound vibrations to your inner ear through the bone, bypassing the eardrum entirely. I’d never regularly worn headphones while riding, mostly so I could remain aware of traffic and the world around me. (It’s also illegal to wear them while riding in New York City, at least in both ears.) I found the Bluez 2S struck the perfect balance between weight and audio output, while keeping situational awareness levels high. The experience is quite different from your traditional headphones, though, so they won’t be for everyone.

The AfterShokz Bluez 2S is a recent update to the Bluez 2 model, adding the new “PremiumPitch+” technology, which aims to boost the bottom end and prevent sound leakage, alongside slight changes to the external design. There are now perforated openings where the speakers rest on your cheek — before it was a solid surface. Even with this seemingly more exposed design, the Bluez 2S still meets IP55 standards for dust and sweat protection, which I successfully confirmed over an exceedingly hot and humid summer in NYC. The open speaker surface and revamped internals do indeed make a difference in audio quality and volume. It may not be profound, but it’s a noticeable improvement over its predecessor.

The arrival of the 2S dovetails with the announcement of the company’s sporty Trekz Titanium, which hit Indiegogo last month and quickly shot past its fundraising goal. Although we haven’t tested those yet, it’s easy to see the benefit from the Trekz’ flexible design. With the rigid U-shaped plastic band of the Bluez 2S that goes around the back of your head, you can imagine the potential for breaking while bouncing around in a bag. That said, I’ve had them packed in both full bags and jostling around in sparse ones, and nothing has happened to them in several months of use. Also, the headband does get in the way of sunglasses to a certain degree. Since the speakers work best when resting snugly against the cheek, I’ve had the arms of the glasses positioned above the band (outside just feels weird), which tends to tilt the glasses down and crowd my face a bit. It’s not a dealbreaker, but it’s certainly not a great pairing.

So how do they sound? First, you need to understand that this is an entirely different experience than regular headphones, with its own set of trade-offs. Music will sound a bit different with this type of technology. The overall sound may be a bit duller compared to your standard cans, but you’ll also get a pleasantly spacious head-feel when listening, which is hard to convey. Speech comes across clearly, but the low-end will be lacking in comparison. I frequently have the volume near maximum when I’m hustling on bustling city streets and feeling the music. In quieter environments, however, there’s more headroom in volume flexibility. The claim is that PremiumPitch+ helps increase bass, while dampening vibration and reducing sound leakage. The Bluez 2S may not be the loudest pair I’ve listened too — Damson’s Headbones still hold that title — but they provide plenty of kick without going overboard on the vibration.

It helps to be a glutton for aural stimulation with bone-conduction headphones. Unlike the isolating experience you get with in- or on-ear models, you get both music and ambient sound leaking in — which is part of the benefit for me. As long as you’re not rocking full volume, you can easily have conversations and hear cars approaching from behind, making it a flexible and safer option if music is a must while riding a bike. For the same reason, they’re great when you’re walking around the neighborhood, but the sound of a New York subway will certainly overpower your tunes.

On the hardware side, you get Bluetooth connectivity, a volume control rocker that doubles as a battery check and EQ changer, power and a multipurpose button on the left earpiece. Since I’m right-handed, the left-side button is perfect for me. It can pause/play music, skip tracks, redial the last phone number and take calls with its onboard mic. The battery life is rated at six hours of continuous play and 10 days of standby. Indeed, it’s great to find the headset charged after neglecting it for a week. It takes about two hours to charge up, but I’ve rarely drained the headset fully, so it seems to top off rather quickly for me. Bluetooth range is the standard 33 feet, letting you pair with a computer and wander around the kitchen or nearby room without stuttering. It stays paired with your last device though, so be sure to check it’s not still tied to the computer if you leave the house and don’t hear your tunes. Also, once paired, if the current track isn’t playing still, try skipping forward or back one.

As a comparison, I tested the Damson Headbones, a Kickstarted bone-conduction model from the UK. First, both models get points for awkward naming conventions. The Headbones do have a lot more features including a line-out for earbuds or as a passthrough for non-Bluetooth speakers. They have a bit more playtime at eight hours, APT-X and NFC support, and fold down into a rigid carrying case. As I mentioned, the audio volume is also significantly louder than the Bluez 2S.

This comes at a price, though: The Headbones are more than twice the weight, with a bulky portion that sits at the back of your neck to house the extra flourishes and battery power. Since I ride with a backpack, the hefty rear section bumped up against it making them difficult to wear. While it pumps out a beefier sound, I found the ear (actually cheek) pieces to be a bit too snug and at higher volumes the vibration was uncomfortable. They’re definitely a quality set of bone-conduction headphones, but didn’t mesh well with my needs and preferences.

The bottom line here is that while you’re not going to have the same audio experience as a standard set of headphones, the benefits of the Bluez 2S outweigh the negatives, at least for me in how I use them. I get a comfortable, lightweight wireless headset that provides tunes at a respectable volume, while still being able to maintain awareness about what’s going on around me — an ideal scenario for bike riding. The AfterShokz Bluez 2S is available for pre-order now for $100, while the Trekz Titanium version should arrive in January 2016 for $130.

Bone conduction technology has been around for many years in the walkie talkie accesory market, it has made a several appearances over the years in the leisure headset/earpiece industry, it is perfect for using whilst driving or cycling, like this article shows,  not having to talk into a mic is a massive plus for using this technology.

Workplace adjustments for employees with a hearing impairment

For employees with a hearing impairment, the presence of sound in the workplace can be a daily challenge and a source of frustration. Robin Christopherson looks at how employers can manage potential problems.

Wherever you work, and whatever your role, there is a strong chance that you are routinely bombarded by noise from a variety of different sources. Telephones ringing, printers whirring, music playing on the shop floor or the constant hum of colleagues talking in a open-plan office, the world of work is full of sound.

According to the Health and Safety Executive, around 17,000 employees in the UK experience deafness, ringing in the ears or other ear conditions caused by excessive noise at work.

Action on Hearing Loss estimates that at least 800,000 people in the UK are severely or profoundly deaf, but this is a small proportion of the 10 million people with some form of hearing loss, of which it estimates that 3.7 million are of working age. There are no exact figures on the numbers of people who use British Sign Language (BSL) to communicate, but the estimate is around 50,000.

An employee’s hearing can be impaired in many ways; there is a whole spectrum of

hearing ability and there are lots of different causes of hearing loss, as well as a variety of possible implications in the workplace.

Types of hearing impairment include:

  • age-related;
  • temporary or permanent;
  • progressive; and
  • environmental factors.

Impacts of a hearing impairment

As hearing is not something we can “see”, it can be difficult to determine whether or not a colleague’s hearing is impaired. This can make it difficult for line managers to know who to help, and when.

In meetings, presentations, networking events or interviews, a hearing impairment could have an impact on an employee’s ability to do their job, if they are not properly supported or if the working environment is not inclusive of their needs.

There can also often be an emotional response to hearing loss, which impacts on the social and wellbeing of the employee. If you are unable to hear what colleagues are saying clearly, you might miss out on vital information needed for your role, or you might miss the latest bit of office banter, which makes you feel isolated and excluded, having a negative impact on morale.

Reasonable adjustments

Employees with a hearing impairment are protected under the Equality Act 2010 and employers are required to remove the barriers that deaf and other disabled people experience in the workplace. There are a number of different ways to ensure that an organisation is accommodating the needs of deaf or hearing-impaired employees.

Benefits of technology

We are all using technology in the workplace, without really thinking about it, as part of our day-to-day communications. How much of the information you share with colleagues or clients is via the phone, email, your intranet, website, a PowerPoint presentation or a short video? The answer is, of course, nearly all of it.

Technology can work as an enabler as well as a disabler. A message from your organisation’s CEO via video on your corporate intranet can be a really powerful way to communicate with your workforce, but if that video does not have subtitles or captions, you are excluding a proportion of your staff, not limited to those with a hearing impairment but also people whose first language is not English.

A variety of technologies can be used in the workplace to support employees with a hearing impairment. There are some specialist programs available that are specifically designed to support people with hearing loss, but many of the mainstream programs and equipment that your organisation already uses could also be adapted at little to no cost. They include:

  • text messaging, and email;
  • amplified sound alerts built into PCs;
  • a flashing screen on a mobile device when a sound alert is triggered;
  • bluetooth to connect to hearing aids;
  • captions for videos;
  • BSL on-demand services;
  • video calling for signing or lip-reading;
  • palentypists and stenographers; and
  • voice recognition speech-to-text software.

Sometimes the most effective adjustments are made by simply utilising existing resources in a different way. For example, if important company announcements are often given over a tannoy or PA system, which would be difficult or impossible for someone with a hearing impairment to hear, you could also issue the same message via email or text message.

There are also times when specialist adjustments, such as using a palentypist or BSL interpreter, need to be arranged. It is important that the individual employee gets the adjustment that they require, when they require it – because no two people with a hearing impairment are the same.

This article highlights the many advancements that have been made in the field of hearing protection at work, and ten years after the Control of Noise at Work Regulations 2005 came into force we should have completely eradicated high levels of noise or the need to control it into the workplace, the original of this article can be found here.