TV ANTENNA INSTALLATION GUIDE

• Band I antennas for channels 0 to 2
• Band II antennas for channel FM
• Band III antennas for channel 5A to 11
• Multi-channel VHF antennas for channel 0 to 11

• Band IV antennas for channels 28 to 35
• Band V antennas for channels 39 to 69
• Band IV/V antennas for channels 28 to 69 (in circumstances)

The following information is provided as a guide. For the best results, you should ask a professional antenna installer to advise on and, if necessary, install your UHF antenna system.

Television signals are strongest, and reception is usually the best, when the station's transmitting tower is in clear line of sight with the home receiving the broadcast. Mountains, buildings or trees, which block this line of sight, tend to weaken and degrade the received signal; the signal also becomes weaker as it travels further from the transmitting tower. All of this means that, in difficult and/or distant receiving situation; a higher 'gain' antenna may be required.

'Gain' is one measure of an antenna's ability to receive signals; the weaker the signal you are trying to receive, the more 'gain' your antenna should have. In practical terms, higher 'gain' antennas are usually longer, and have more elements or cross-pieces.

It is important to realise that an antenna's 'gain' can vary from channel to channel; for example, an antenna's advertised 'gain' rating may apply to channel 28, but the 'gain' may be much less at channel 55. Make sure your antenna supplier guarantees that the antenna you buy is suitable for all the channels in your area.

The boom (backbone or spine) of the antenna is pointed towards the source of the broadcast, the transmitting antenna. The elements (cross-pieces) should be adjusted to be horizontal or vertical depending on whether the transmitted signal is horizontally or vertically polarised. tvantenna.com.au  can advise on the polarisation of your service. The direction in which the antenna points and its height should be carefully adjusted to obtain the best picture. Small changes can make a big difference. "Subject to area you are calling from."

If your picture is spoiled by 'snow', by 'ghosting', or by both of these undesirable effects, these pointers may help:

• 'Snow' or severe 'grain' in the picture is caused a weak signal, a poor antenna system, the set itself or by a combination of these.
• 'Ghosting' is caused by a signal arriving at your antenna from two or more different directions. These multiple signals cause multiple images (or ghosts) on your screen; they occur when the main signal is reflected off buildings, mountains or even aeroplanes.

If you are starting from scratch, or if your present VHF reception is not very good, you should study this guide carefully before attempting an installation and seek further advice if you are not confident about all the details.

UHF conversion or adaptation of a VHF antenna system connected to multiple TV sets is more complex, and you should always consult a reputable antenna installer who has experience in the installation of these systems.

The correct antenna cable will deliver the television signal from the antenna to the set, with relatively little loss of signal level or quality. Installing the correct cable is as important as choosing the correct antenna. The main points to remember are:

• Conventional ribbon-type VHF cables are not suitable for UHF.
• You need to use a low-loss coaxial cable

A good quality 75 ohm low-loss UHF coaxial cable is recommended. It is suitable for both VHF and UHF signals and is easy to install. It has greater resistance to the weather and is less likely to pick up unwanted signals than an unshielded ribbon-type cable.

Coaxial cable on an existing VHF antenna installation may not be suitable for UHF reception and should be treated with caution.

Most new television sets are fitted with one (combined UHF/VHF) input socket for coaxial cable. The cable must be fitted with a proper coaxial plug to fit these sockets.

COAXIAL CABLE

Use low loss coaxial feeder cable to connect the antenna to the TV set. This cable should be suitable for the new digital television service. This type of cable is suitable for both VHF and UHF signals.

We recommend rg6 quad shield for the best result.

Use the shortest possible length of cable as this will mean reduced signal loss. Prevent wind damage by attaching the cable firmly to the outside wall. Form the cable into a half-loop where it enters the house so that rainwater will drip off. Seal the entry point with a waterproof sealant.

AMPLIFIERS

If you use a splitter you will find that signal strength is reduced and that you may need a masthead or distribution amplifier. This equipment boosts the signal before it is fed into the splitter and ensures that signals of adequate strength are supplied to each connected set.

A professional antenna installer can measure the signal strength at your home and recommend the type of equipment needed.

Combined Splitter/Amplifiers are also available.

	In order to minimize the effects of power surges, built-up static electricity or lightning, you will need to ground your antenna. The ground should run in a straight line, with minimal changes of direction and without sharp bends. Use the utmost care and take all safety precautions included with the antenna and any accessories, or hire a professional to do the work.	fig 1