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out picture, possibly causing a breakup in the trans- mission or noise in the audio portion. The most com- mon faults in these two examples are either an im- properly exposed camera or signal loss due to a long cable run from the camera to the transmitter. If these problems are not too extreme, the DA can correct them by its gain and equalizing functions. To operate, the DA must be connected to a waveform monitor to display the effects of any adjustments.

The four basic ways of transmitting a live picture from the field are by means of the following:

Telephone lines Fiber-optic lines Microwaves Satellites

Telephone Lines

The local telephone company can set up a video-feed point from just about anywhere using a balanced line (different from a regular phone line). Because of the time necessary to set up this type of transmission, it is rarely used except for events such as election returns where there is plenty of lead time for installation. Be- cause of deregulation in the telephone industry, it can be a challenge to find the right company or unit to de- liver such a line, but most phone companies have ex- perience with this method of delivery. The lines can be run to just about anywhere that has phone service.

Fiber-Optic Lines

Similar to regular phone lines, newer phone systems have light-transmitting cables already in place. These fiber-optic lines carry light-encoded video and audio information to distant distribution centers with little loss of signal. This system’s benefits are best seen when using digital signals. Special encoders and decoders are needed at each end of the fiber line to change video and audio signals into laser light and back again.

Microwaves

Microwave equipment is relatively small and usually owned by the TV station using it. The most common placement of a microwave system is in a van (some-

times called a live truck, RF truck, or feeder) that has an antenna at the top of a telescoping mast that may go as high as 50 feet. (See Figure 2-9.) The truck usu- ally has a reel of multiline cable (two video and four audio lines in one cable) that can stretch about 300 feet. A normal video cable allows up to a 1,000-foot run before the loss of signal becomes too great for the DA to compensate.

Microwave transmitters work in a spectrum of radio-frequencies measured in gigahertz (GHz) and have specific channels assigned by the Federal Com- munications Commission (FCC). The standard ENG channels have always been 2, 7, and 13 GHz. Each channel can be subdivided further into parts simply called A, B, C, D, and Center, with the option of the microwaves going clockwise or counterclockwise. These variations allow many stations in the same mar-

Figure 2-9 Satellite and microwave trucks (feeders) are a common sight wherever major news events occur.

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ket, or many transmitters at one station, to transmit at the same time. With the increased use of this technol- ogy, more channels have been opened up, including 2.5, 6, 6.5, 10, 12, and 40 GHz. Generally, the lower the channel number, the easier it is to transmit over long distances.

A microwave link can transmit up to 50 miles if there are no obstructions. Microwaves need a clear line of sight from transmitter to receiver to work. This is why the antenna (either a dish or golden rods) is on a mast and the receiver is usually on a mountaintop or the tallest building; the signal can then go from there to the station by a secondary microwave link or hard line (telephone lines). Because the microwave beam is very narrow, it is essential that the transmitting and re- ceiving antennas be pointed precisely at each other. (See Figure 2-10.) When they are many miles apart, this is not an easy task. Experienced people at each end can accomplish this in a very short period of time— sometimes in seconds, if the operators are very good.

While the truck-mounted microwaves are usually on channels 2 or 7, a portable system called a mini-mic uses channels 13, 18, and 40 GHz. This shoebox-size transmitter can be placed in a backpack for the camera operator to wear; it can also be mounted on a small tri- pod near the camera to take the place of what might be a hard or impossible cable-run back to the live truck. Because the range of this small transmitter is limited, a mini-mic is primarily used in sports coverage or to re- place a cable where mobility is the critical factor (e.g., from a high floor of a skyscraper). The receiver is at the live van where the signal is retransmitted to the station.

Satellites

With so many satellites in orbit today, almost anyone who has an uplink or downlink (a ground-to-satellite transmitter or receiver) can buy satellite time. With the advent of 24-hour news channels, such as CNN, trans- mitting breaking stories live to the whole country has become a must. While microwaves are limited to less than 50 miles and line of sight (although they can be relayed or hopped to greater distances), a portable sat- ellite uplink mounted on a truck can go anywhere there is a road and sky. (See Figure 2-11.) Today, most stations in the top 100 markets have satellite trucks.

Many memorable TV moments have reached our eyes and ears via satellite. Some events allow for plan- ning, including time and space to set up large-scale feeds, such as Princess Diana’s wedding and funeral in London, or the World Cup soccer tournament in Ger- many. Other events do not provide the luxury of time and space, such as reports from journalists in Afghani- stan and Iraq who are “embedded” with military units, giving them unprecedented access to war coverage but no lead time and no luxuries. In these latter cases, the reporter usually uses an uplink system called a fly-away that is small enough to be folded down and shipped as airline baggage. (See Figure 2-12.) Powered by batter- ies, a fly-away system can be used in any remote area without any utilities. The batteries can be recharged by

Figure 2-10 A microwave truck with its transmitter atop an extended mast for a clear line of sight with the receiver.

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