FM RADIO TRANSMITTER CAR KIT For Apple iPod / iPhone / iTouch / Nano / iPad

 FM RADIO TRANSMITTER CAR KIT For Apple iPod / iPhone / iTouch / Nano / iPad

FM RADIO TRANSMITTER CAR KIT For Apple iPod / iPhone / iTouch / Nano / iPad








Tuesday, March 27, 2012

History of the Media, Radio, and Television

History of the Media, Radio, and Television


When were the forms of media created? When did advertising first show up? Who owns the media?

History of the Media, Radio, and Television

History of the Media, Radio, and Television

History of the Media, Radio, and Television


History of the Media, Radio, and Television



History of the Media, Radio, and Television

Creation of the various forms of media

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Newspapers & Magazines ~ 1880

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Movies ~ 1910

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Television ~ 1945

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Cable Television ~ 1980 's

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Satellite Television, the Internet, Digital Communication ~ End of the 20th century

In 1920, radio was first developed, primarily for use by the military, strictly for sendingHistory of the Media-Old Radios messages from one location to another. David Sternoff, the then-president of RCA, first had the idea to sell radio sets to consumers, or what were then called radio receivers. However, consumers needed a reason to buy radios, so RCA was the first to setup radio stations all over the country. Between 1920 and 1922, 400 radio stations were set up, starting with KBKA in Pittsburgh. Stations were also set up by universities, newspapers, police departMents, hotels, and labor unions.

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By 1923, there were 600 radio stations across the United States, and $ 83 million worth of sets had been sold.

The biggest difference in radio before and after 1923 was that the first advertising was not heard on the radio until 1923. RCA at the time was made up of four companies:

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AT & T

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General Electric

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United Fruit

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Westinghouse

United Fruit was one of the first global corporations, and one of the first to advertise on the radio. TheAT & T division of RCA first thought about selling time on the Air to companies, which marked the start of "toll broadcasting." WEAF was the first station to operate this way, causing widespread outrage, and accusation of "polluting the Airwaves."

Because of this controversy, the practice of selling advertising time was called "trade name publicity." Sponsors linked their name with a program on the air, rather than advertising a specific product in a 30 second "commercial" as we know it today.

Why did AT & T decides to experiMent with charging companies for air time?

AT & T was not making any money from broadcasting at the time since they only made transmitters, receivers. They only made money when new radio stations bought the equipment requiredto broadcast. They did not make money from consumers buying radios.

AT & T also started the practice of paying performers for their time on the air, rather than only volunteers, which was standard practice for radio content up until that point.

The first radio network

In 1926, RCA set up the first radio network, NBC. They decided it was more effective and efficient to produce shows in New York City, and then link the main radio station with stations all across the country, connected by AT & T (another RCA company) phone lines. (Now television networks are linked by satellite to their affiliates).

This was the beginning of the network affiliates system. The ideal network makes sure everyone in the country is capable of listeningto their signal. NBC at the time had two philosophies:

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Radio content was a "public service," whose function was to sell radios.

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Radio content was designed to generate income from advertising.

History of the Media In 1927, the second network was formed. It was CBS, started by William Paley. Paley was the first to think that networks could make money strictly from advertising, not even getting involved in the sales of radios. Like AT & T, CBS did not make radios. From the start, they made their money from selling advertising.

The rising of radio networks caused the Radio Act of 1927 to be passed, which established the FRC, or what is now known as the FCC to allocate broadcasting licenses. The need for such anorganization was brought on by the fact that airwaves are limited resources, and broadcasting itself is a scarce public resource. By the 1930 's, the structure of radio have been set by the commercial format, although advertising never dominated radio like it would television later on.

In the 1920 's and ' 30 's, radio programs were divided into two groups. Sponsored shows, which had advertisers, and unsponsored shows, which did not. The radio station paid for the unsponsored shows. The sponsored shows, on the other hand, were created enTirely by the company sponsoring the show; advertisers were totally in charge of the radio station's content. The content became advertising. Radio set the precedent for television, in that the samecompanies that controlled radio early on went on to control television.

Soon thereafter, television inherited the structure of radio. In the ' 40 's, during the rise of television, RCA also held a monopoly on all television sets sold. By 1945-1955, advertising had taken over all of television. Television was organized around the premise of selling things. The enTire television industry was creating a political atmosphere of suspicion and fear. Senator Joseph McCarthy, the founder of McCarthyism, which was based on the fear of Communism, and the HUAC (the House UN-American Activities Committee, began to question people involved in television about their beliefs and associations.

What affected television in its early sTAGes?

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Politics (McCarthyism/HUAC).

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Blacklists: From almost the inception of television, many writers, directors, and actors were considered to be pro-Communist and/or UN-American.

Certain topics were totally off-limits at the time for television, particularly issues of race relations in the 1960 's. Overall, networks were not happy with the political situation for television in the 1960 's, both in terms of the blacklists, and of the fact that when every show had one sponsor, sponsor that controlled the entire program. Networks preferred to control the program, by way of moving to multiple sponsors/advertisers, where networks would retain control of the show, and advertisers would buy time in between the programming.

In the 1950 's, networks decided to eliminate the practice of sponsorscontrolling the shows with a move to selling commercials between programs, or advertisements, as we know it today. What caused the move to commercial selling?

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Discovery of fraud in the quiz shows on television. Quiz shows were extremely popular at the time, and were liked by the networks, the sponsors, and the viewers alike. It turned out, however, that quiz shows were largely fixed. Charles Van Doren on "21" became a huge star due to his repeated wins, until it came out that the whole thing had been fixed. In the case of "The ,000 Question," the owner of Revlon was personally hand-selecting the winners and losers on the show.

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It was becoming financially difficult for just one advertiser to support an entire show.

Around this same time came the inception ofratings to measure to the show's popularity. Ratings, quite simply, measure the number of people Watching a show. To understand why ratings are so important, it's crucial to understand how the television industry works, through three questions and their respective answers:

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Who owns television? [The networks]

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What is sold on television? [Viewer's time, not television shows]

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Who are the customers of television? [Advertisers, not viewers]

This might be a counterintuitive concept for some. The networks, which own television, areHistory of the Media-the buyers of Old Television shows, not the sellers. On the other hand, they sell our eyeballs, so to speak, to advertisers. Networks want the maximum possible profit from buying and selling time,both viewers ' time, and advertisers ' time.

The primary measure of television ratings, which determine the price of that time being bought and sold, is AC Nielsen, an independent company which provides information as to who Watches what on television. Currently, about 4.000 households are used to represent the national viewing of television. In the 1980 's, only 1.200 households were used. Some households have an electronic device installed on their television which tracks what they Watch, while others keep a diary of viewing habits.

There are two measures for determining a show's audience. One is the rating, and the other is the share.

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Rating: PercenTAGe of total homes with televisions tuned into a particular show.

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Share: PercenTAGe of those Watchingtelevision at a particular time who are tuned into a particular show.

The share is always greater than the rating. Ratings are more important for advertisers, and share is more important to the networks.

Example:

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Total households with televisions: 150 million

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Total households watching television at 8:0 pm on Monday nights: 90 million

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Total households watching American Idol at 8:0 pm on Monday nights: 45 million

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Therefore: Rating: 30, Share: 50

It's important to note how many factors can skew the results. Shows cost producers much more than the networks typically pay them for those shows. The way for producers to make money is by getting the networks to renew the show, in order to have a shot at making money fromsyndication on other channels, also knows as reruns. That is the case when individual stations (say for example, the Miami affiliate of ABC wants to carry Seinfeld), buy the rights to a show from the producers of that show. Shows that last only one season, for the most part, lose millions of Dollars. One of the most important factors in whether shows will be renewed or not is their rating.

This brings us to how ratings can be skewed. For example, if a show has a 20 share, and it needs a 25 share to be renewed for another season, what might the producers do? In principle, they need to convince another 5% of the people watching television when their show is on to watch their show; this is no simple task, as that involves convincing millions of people. However, since the ratings arebased on those 4.000 Nielsen households, that means that they could convince just 200 Nielsen households to watch their show, which would increase the share from 20 to 25. This is why Nielsen households must be kept totally secret from the networks. When the Nielsen households have leaked to the networks, one way which they got people to watch their show was by offering viewers a small sum of money for filling out a survey about a commercial which they were told would play only during a particular show. Since they had to watch that channel while their show was on, this would boost the share.

Once ratings are determined, advertising prices are set by two factors:

* The size of The audience.

* The demographics (income, age, gender, occupation, etc.) of theaudience.

In short, the Job of television programs is to collect our time as a product, which they then sell to advertisers. Programs have to support the advertising, delivering viewers in the best possible state of mind for buying when the time for the commercials comes, which brings us to the Golden Age of Television.

The 1950 's are considered the "Golden Age of Television." During this time, something called the "Anthology Series," where different actors each week took part in a show gained History of the Media-I Love Lucypopularity across the board ... that is, with everyone except for advertisers. The anthology series format was not right for advertisers, as it covered topics which involved psychological confrontation which did not leave the viewers in the proper stateof mind for buying the products shown to them between program segments. The subject matter of the anthology series was of the type that undermined the ads, almost making them seem fraudulent.

This brought up the question of what to network executives actually want shows to do? The answer is not to watch a program that makes them feel good, makes them laugh, or excites them, but rather to watch the television for a set amount of time. With so many new shows being proposed, standards began to be intentionally, or unintentionally, laid out for what shows could and couldn't do. Risks could only be taken at the beginning and/or end of shows. Laugh tracks were conceived to tell the audience when to laugh. Programs began being tested with audiences prior to being put on television and/orradio. Show writers now had to write shows that would test well.

Naturally, this caused many of the same elements and themes to appear on all shows. This was the beginning of recombinant television culture, where the same elements are endlessly repeated, recombined, and mixed.

This same culture is perpetuated the idea that what people watch television, not specific shows. While people certainly choose to watch certain shows instead of others, people less commonly choose to watch television instead of other things. People watch television. Regardless of what was on television viewing rates were extremely stable.

History of the Media, Radio, and Television

Thursday, March 8, 2012

UHF Versus VHF-Which two-way Radio Frequency is Better?

UHF Versus VHF-Which two-way Radio Frequency is Better?


There are two major formats for two-way radios. They are Ultra High Frequency (UHF) radio and Very High Frequency (VHF) radio. Neither frequency band is inherently better than the other. They each have their pluses and minuses. Both formats are effective ways to communicate with another person. But how do you decide which one will fit your needs? Let's go over the key components of both frequencies to help you decide.

UHF Versus VHF-Which two-way Radio Frequency is Better?

UHF Versus VHF-Which two-way Radio Frequency is Better?

UHF Versus VHF-Which two-way Radio Frequency is Better?


UHF Versus VHF-Which two-way Radio Frequency is Better?



UHF Versus VHF-Which two-way Radio Frequency is Better?

Two-way radios communicate with each other through use of radio waves. Radio waves have different frequencies, and by tuning a radio receiver to a specific frequency you can pick up a specific signal.

Radio waves are transmitted as a series of cycles, one after the other. You will always see the "Hz"abbreviation used to indicate the frequency of a radio. Hertz is equal to one cycle per second.

Radio waves are measured by kilohertz (kHz), which is equal to 1000 cycles per second, or megahertz (MHz), which is equal to 1.000 .000 cycles per second--or 1000 kHz. The relationship between these units is like this: 1.000 .000 Hertz = 1000 kilohertz = 1 megahertz.

You may also hear the term "wavelength" when you hear about radio waves. This term is from the early days of radio when frequencies were measured in terms of the distance between the peaks of two consecutive cycles of a radio wave instead of the number of cycles per second. Lower frequencies produces a longer wavelength.

While wavelength measures distance between the peaks ofcycles, frequency refers to how long the measured time is between the "crest" and "trough" of a wave arriving at the source. So frequency measures time instead of distance, but they are essentially both saying the same thing.

What is significant about wavelength for two-way radios is that it affects transmission range under certain conditions. A longer wavelength as a general rule lets radio signal to travel a greater distance.

Lower frequencies or wavelengths have greater penetrating power. That's one of the reasons they are used for communicating with submarines. VLF radio waves (3-30 kHz) can penetrate sea water to a depth of approximately 20 Meters. So a submarine at shallow depth can use these frequencies.

So from what you read above you may think VHFis always the better choice for a two-way radio no matter where you are using it. That's not necessarily true. Even though VHF has better penetrating capabilities, that doesn't necessarily make it the better choice for buildings. Remember the conversation about wavelength above? Wavelength has a big impact on transmission.

To explain this let's assume we are communicating from one side of a commercial building to the other. In between these two points is a metal wall with a three foot door in it. Metal is an enemy to radio waves and they typically don't pass through it.

For our example let's assume that the wavelength the UHF radio uses is about a foot and a half long and a similar VHF radio is around five feet long. These are in the ballpark oftheir normal wavelengths.

When the UHF transmits its signal the foot and a half long wave will pass through the door since the door is wider than the wavelength. The VHF signal will be totally reflected since it is wider than the opening to the door.

Your microwave oven is an example of this. The glass front door has a metal mesh with very small holes. Microwaves being a very high frequency have wavelengths that are only several inches long. The mesh keeps the microwaves trapped in the oven but it allows you to see inside because light waves have a wavelength microscopic.

Just imagine walking through the building carrying a five foot wide pole. You will encounter the same challenges to VHF signal encounters. Now imagine walking through the building with a pole that's onlya foot and a half wide like a UHF wave. There are lots fewer doorways you couldn't get through.

The one difference is that wireless signals will penetrate through drywall, masonry, human bodies, furniture, wall paneling, and other solid objects. All these objects will reduce the signal strength though. The more dense the object, the more it reduces the signal. VHF will penetrate these obstacles better than UHF, but that doesn't necessarily mean that VHF is better for indoor applications as we will talk about in the UHF section below.

In our example above we assumed you had a metal wall with an opening. If you reverse this and you have a three foot metal object in front of the transmitting radio, then VHF would win. Since the object is three foot wide it will totallyblock the UHF signal whereas the VHF signal will get around it. Lower frequencies diffract around such as VHF large smooth obstacles more easily, and they also travel more easily through brick and stone.

For most applications, lower radio frequencies are better for longer range. A broadcasting TV station illustrates this. A typical VHF station operates at about 100.000 watts and has a coverage radius range of about 60 miles. A UHF station with a 60-mile coverage radius requires transmitting at 3.000 .000 watts.

So there is no clear choice for which is better, VHF or UHF. There is a lot of "black magic" to radio technology so it's not always easy to tell which will work better for your application. To help you decide on the best technology for you, more detailabout each one is included below.

UHF Radio

UHF equipMent operates between the frequencies of 300 MHz and 3000 MHz. Until recently, it wasn't widely used. Now, the UHF radio frequency is used for GPS, Bluetooth, cordless phones, and WiFi.

There are more available channels with UHF so in more populated areas UHF may be less likely to have interference from other systems. If you are in an area where population is thin, VHF should work fine for you. Not too long ago the FCC also opened up a new VHF frequency called MURS that is so far not heavily used in most areas. There's more about MURS below in the VHF section. If you are in an area where interference from other radios may be an issue, UHF transmitters and receivers could be your bestchoice unless you use a MURS VHF radio. UHF is better at squeezing through physical barriers like walls, buildings, and rugged landscape. Anything that obstructs a radio wave, will weaken a radio signal. UHF lessens that effect. Though it may not travel as far, UHF radio waves will traverse around obstacles better than VHF.

To highlight the differences in indoor range, below is an excerpt from a brochure of a leading two-way radio maker on the predicted range of one of their lines of handheld VHF and UHF two-way radios:

"Coverage estimates: At full power, line-of-sight, no obstructions the range is approximately 4 + miles. Indoor coverage at VHF is approximately 270.000 sq ft and 300.000 sq ft at UHF. Expect about 20 floors verticalcoverage at VHF and up to 30 floors at UHF. Note: Range and coverage are estimates and are not guaranteed. "

VHF RADIO waves are not very good at finding their way around walls, buildings and rugged landscape. Therefore range will be significantly reduced for VHF radios in these environMents. That may not necessarily be a problem if the range needed is only a few hundred feet. You can also add an external antenna to an indoor VHF base station that will reduce or eliminate this problem.

One of the downsides to UHF is that the FCC requires you to get a license to operate on these frequencies. Although many frequencies in the VHF band also require a business license. If you choose a radio in the VHF MURS frequencies you can operate it without a license. UHF equipMent is usuallymore expensive. The components need to be finely tuned and are more expensive to construct. This does not mean it's necessarily better, just more expensive.

One advanTAGe of UHF transmission is the physically short wave that is produced by the high frequency. That means the antenna on the radio can be shorter than an equivalent VHF radio.

VHF Radio

VHF equipment operates between the frequencies of 30 MHz and 300 MHz. FM radios, two-way radios, and television broadcasts operate in this range.

Both UHF and VHF radios are prone to line of sight, but factors VHF a little more so. The waves make it through trees and rugged landscapes, but not as well as UHF frequencies do. However, if a wave and a VHF UHF wave weretransmitted over an area without barriers, the VHF wave would travel almost twice as far. This makes VHF easier to broadcast over a long range. If you are working mostly outdoors, a VHF radio is probably the best choice, especially if you are using a base station radio indoors and you add the external antenna.

Since VHF has been around longer and isn't as complicated to make, equipment is usually cheaper when compared to similar UHF equipment. One disadvanTAGe to this equipment can be its size. Since the frequency waves are bigger, an antenna must be bigger.

VHF radios also have a smaller number of available frequencies. Interference with other radios could be more likely to be a problem. However, the FCC recently made this less of a problem when they opened upthe MURS frequencies. The 150 MHz frequency is a Citizens Band radio spectrum that is called the MURS service. MURS stands for multi-use Radio Service. This service is for use in the United States and Canada. It is a low power, short range service in the VHF 150 MHz Citizens Band radio spectrum. There are 5 channels in the MURS frequencies with 38 privacy codes under each one that enable you to only pick up conversations on your code. The FCC does not require users of products for MURS to be licensed.

With MURS, you can add a larger or external antenna to improve range. If you want to put an antenna on top of your house or business, you can do it with MURS. Some antenna manufacturers claim an external antenna can increase the effective radiated power of a> transmitter by a factor of 4. These MURS intercoms can transmit up to four miles, and perhaps more with an external antenna depending on the terrain.

One benefit of VHF wireless radios is that battery life is almost always better than for similar UHF units. For handheld radios this is a plus.

VHF equipment is usually lower cost for those on a budget. Equipment can be more economical than similar UHF products.

UHF Versus VHF-Which two-way Radio Frequency is Better?