Tuesday, December 13, 2016

What 2 Way Radio Channel Should You Use

You may get confused about various types of walkie talkies on sale in the UK, or not be certain what type of walkie talkies you require, and what you’re legally allowed to use in some other countries that you plan to visit, or in your part of the world. Firstly, it is important to have in mind that any type of walkie talkie will function in any part of the world.
A walkie talkie is used on a channel that has a frequency associated with the walkie talkie. In other words, if a channel has a frequency different from that of a walkie talkie, then the two will not work together.
License Free Walkie Talkies
There are 446 license-free frequencies that can be used for leisure radios such as, Motorola talkabout, Binatone and Cobra radios. However, there are eight PMR466 frequencies or PMR466 channels that can be used.
The spacing between each of these frequencies is 12.5 kHz. As the system name suggests, PMR446 frequencies are located around 446MHz and are in the UHF segment of the radio range.
Even though they are not necessarily authorized, PMR446 frequencies are harmonized for use across European countries.
High level use of PMR446 frequencies may result in some annoying problems. However, these can be reduced or rectified by changing the frequency of the PMR446. Other systems such as DCS codes and CTCSS tone can as well help in alleviating the problems.
In view of the possible high use of the frequencies and the PMR446’s unlicensed nature, the scheme is not appropriate for individuals who need to gain access to frequencies at specific times and locations or for life use.
These are simple, short-range walkie talkies that conform to the European Union-wide PMR446 standard and can be used by any person in the United Kingdom or European Union without a license. These types of radios are commonly sold in High-Street shops as well as in most radio outlets.
Commonly known as "PMR446s” radios that meet these standards usually have a power output of 0.5watts, meaning that their range is lower compared to the powerful business walkie talkies that are a licensed and which feature power outputs of 4-5 watts. All of them make use of the same eight channels and this causes problems sometimes if a given area has a lot of radio users using these channels.
Licensed Walkie Talkies
Two Way Radio for Business
Licensed handheld walkie talkies can have a power output of 5 watts, but "license free" PMR446 walkie talkies can only have 0.5watt power output. Therefore, the licensed walkie talkies usually have a better signal penetration and better range in buildings.
A majority of businesses prefer using a licensed 2-way walkie talkie system because, in spite of the benefits of license free walkie talkies (PMR 446), they have some downsides (like lower power, a short range and interference) which make them less effective than licensed business radio systems.
Taxi as well as other transport companies, and large sites like factories or hospitals, and businesses situated in a number of different locations are excellent examples of circumstances where a licensed radio system may be a favored option.
These situations require more powerful radios as opposed to hand-held portable walkie talkies with low frequencies. If the system of your radio relies on vehicle-mounted radios or a base station, a licensed radio system is necessary.
If you want start using a radio system in your business, then you will have to get a license from Ofcom. In other words, Ofcom is a company that controls who can transmit on what frequency and where, to ensure that different users don’t interfere with each other.
Business radio system users range from factories and taxi companies, to industrial sites, hospitals, transport operators and care homes. To begin Ofcom’s licensing process there are a number of requirements that a business must first of all fulfil.
Ofcom license is especially important regarding official radio users like police, military, railways, air traffic control and emergency services, railways, etc. Radio systems that meet specific standards can be used without any license from Ofcom. For many walkie talkie users, license free radios will be okay. And if you are in need of a license, it isn’t that expensive or complicated to get one.
The UK simple license is a license issued by Ofcom and gives holders the right to use more powerful radios. It is effectively a license to use powerful radios any place in the UK, using give frequencies which are shared by anyone using this license. This license is easy and quick to apply for, costs about £75 per organization, and is valid for 5 years.
It is the only option for people who need to use their radio systems anywhere in the United Kingdom, and is ideal for most business radios users.
Geographic License
This license provides you with specific frequencies or frequency allocated just for your organization’s use within a given geographical area. The cost of the license varies from moderately cheap in most locations in the UK (about £100 annually), with the cost heightening in key cities, more so London, where the demand for radio frequencies is very high, going for up to more than £500 per year.
Radios that are designed to use dedicated frequencies such as this, should not be used outside of the licensed area, since the same frequency will possibly have been assigned to somebody else and you will therefore be causing interference to them.
UK Business Radio Suppliers License
This is a license for hire companies and radio equipment suppliers. It allows these companies to do short term radio hire via a set of frequencies allotted to radio hire companies. It also allows these companies to provide ‘demo’ radio systems to potential customers and to undertake repairs to radio systems.
When these companies hire out their radio equipment, it’s hired using this license, so that the person hiring it does need to worry about licensing issues.
The importance of walkie talkies and radios in the UK and other parts of the world cannot be overlooked. Not only are these gadgets important in everyday communication, but they continue to play a very crucial role in the development of other communication tools. A lot of useful information about radios and walkie talkies has been highlighted in this article for the benefit of radio users and the public in general.

Sunday, November 20, 2016

what to look for when buying earphones

Closed Back Headphones vs. Open-back Headphones

Open-back headphones have pads which rest on the outer ear. They're designed such that the outer shell of the ear cup has perforations usually with horizontal cutouts. The Open back headphones design of the ear cup enhances better natural sound because of less coloration as compared to the Closed back headphones.
Closed back headphones have much larger earpads which encircle the ears. They are designed such that there's a big pad which cups the ears, and it features an insulated outer shell of plastic which covers the ears. The Closed back headphones actually have a very solid outer shell which doesn't have any sort of perforations such that the outer shell effectively cups/encircles the entire ear. The Closed back headphones are excellent at isolating noise. They block most of the ambient noise, but they've a smaller sound stage, which gives the user the perception that the audio/sound is originating from within their head. Closed back headphones also tend to produce much stronger low frequencies as compared to Open back headphones.
Low Impedance vs High Impedance
Headphones normally come in various different impedance levels, such as 8 ohms, 16 ohms and 32 ohms. The power that's supplied by an audio source may be at varying levels because of a variety of factors including being limited because of being battery powered. Generally, as the impedance of the headphones increases, much more voltage will be required in order to drive it, and the audio loudness of headphones for a particular voltage decreases.
The determination of impedance is usually disregarded by many headphone buyers, however, the truth is it's one of the most important factors to consider when choosing the best headphones for your particular needs. Impedance is basically just how much power the headphones can put out so that it can overcome resistance to move the headphones' diaphragm.
Low impedance headphones (that is, less than 25 ohm), usually require little power in order to deliver high audio levels. Low Impedance headphones play well with devices which have weak amplification. These can include; mobile phones, portable music players and various other portable devices. This type of headphones can be used at home and also while jogging with your mobile phone; this is one of the reasons why most of the on-, in-, and over the ear headphones, are low impedance. Low impedance headphones are normally designed to get plugged directly in to a single (one) source, and generates sound more efficiently from a lower level input signal. This headphones tend to be much louder and much more efficient, however, they will also require a much more capable amplifier.
High impedance headphones (25 ohms and above), generally require more power in order to deliver high audio levels. As a result, they're protected from damages caused by overloading. High impedance headphones are typically designed for studio like applications where there might be multiple phones/devices wired in parallel and receiving input signals from a single source. High impedance headphones are more tolerant of the amplifier limitations, however, they will produce less volume for a particular output level. They are also a little more durable (that is, electronically), however, they require much higher signal levels in order to produce the same level of output level of the low impedance headphones. This type of headphones can be used with a wider range of audio equipment.
Passive Headphones vs. Active Headphones
Passive (noise cancelling) headphones are made of materials which help in blocking out sound waves from the surrounding environment. The same way ear muffs soften the outside noise, so does this type of headphones employ passive noise canceling. This type of headphones are typically used for both professional mixing and monitoring, like in broadcast and recording studios, and such other applications. Passive headphones are basically designed to playback music/audio true to the actual original recording, with minimal, compression, EQ, and such other sound enhancements.
On the other hand, Active headphones use batteries in order to power the built in Digital Signal Processing (also abbreviated as DSP) technology which processes play back for a particular reason, for example, to enhance the bass and the high end. Due to the enhancement of playbacks with sharper high ends and more bass, active headphones are more popular for general listening and listening to music for pleasure. Active noise cancelling headphones are also made of materials which help in blocking out outside noise, however, they take things a step further by making their very own sound waves; the sound waves created mimic the outside noises, but are a mirror image of each other, thus cancels each other out.
Wired Headphones Vs Wireless Headphones
When choosing a pair of headphones, deciding between wireless vs. wired is among one of the most overlooked factors. Wireless headphones might be a more popular choice, however, the wired headphones also have their own set of benefits. Well, that being said, as a general rule of thumb, between wireless headphones and wired headphones, assuming a similar price between the models; the wired headphones usually offer a much better quality. Also, the audio quality may get compromised over Bluetooth.
You can opt for the wireless headphones if you are not much of an audiophile, and you tend to travel a lot. If you really don't like getting the cables of your headphones getting tangled, or caught while listening to music/audio, then the choice should be rather simple; go for wireless headphones.
You can opt for the wired headphones if you are an audiophile, and you do not necessarily bother with the wireless options unless absolutely essential like using them when traveling, or keeping the headphones as a backup. As aforementioned, the wired headphones are way ahead in terms of output quality as compared to the wireless headphones. You will never have to worry about running out of batteries, unless you happen to opt for wired headphones which cancel noise. In addition, you will never suffer from interference from the other commonly used wireless electronic devices. However, you will need to take good care of the wired headphone cables, or they will eventually break.