How to improve your television reception

In Australia Television stations operate in either the Very High Frequency (VHF) or Ultra High Frequency (UHF) bands.

VHF channels are numbered 0 to 11 and UHF channels 28 to 69.

UHF is widely used throughout regional Australia by the ABC, SBS and many commercial stations. Most new TV services transmit on UHF because the VHF band, which shared with FM radio, has become overcrowded.

How to tune your television
  Automatic tuning
  Rotary tuning
  Push button tuning

How to install your antenna
    Choosing the right antenna
    Mounts or Masts
    Installation tips
    Positioning your antenna
    Coaxial cable
    Connections
    Antenna Connection
    Diplexer
    Splitter
    Amplifier
    FM  filters
    Down converter
    Master antenna system

How to tune your television

Each television set is a little different and you should follow your set’s instruction manual when retuning; however, you might find this a useful guide.

Automatic tuning
If your TV set has ‘automatic’ or ‘digital push button’ tuning, then just push the appropriate button and your pre-set channel UHF and VHF will appear. When activated, the automatic tuning device will search for and memorize TV channels as they are located and display the number automatically selected for that channel.

Rotary tuning
If your TV set has a ‘rotary tuner’, then retuning is simply a matter of carrying out the following steps:

• Switch off the AFT (automatic fine tuning).
• For VHF - select the desired channel on the ‘main dial’ and adjust the fine tuning ring until the picture appears at its clearest.
• For UHF - select ‘U’ on the ‘main dial’, then turn the ‘UHF channel selector’ knob to the desired channel.
• Switch on the AFT again.

Push button tuning
If your TV set has ‘push button’ tuning:

• Switch off the AFT. Sometimes this is done automatically when the tuning drawer (or door) is opened.
• Push the button on which you want the new channel to appear.
• Open the tuning drawer (or door) on the set. This will reveal a series of selectors and tuning wheels. Each selector and its adjacent tuning wheel is associated with a tuning button on the front of the set. For example the third tuning button is connected to the third selector switch and the third tuning wheel.
• Set the selector switch to the range of channels required. Labeling of these channel ranges varies from brand to brand, but is usually one of the following:

 

VLF	VHF	UHF
Channels	Channels	Channels
0 to 5	5A to 11	28 to 69
1	2	3
A	B	C
VL	VH	U

• Now, turn the corresponding tuning wheel slowly clockwise until the channel you are seeking appears on the TV screen or until the little pointer indicates you have reached the end of the tuning range. If the selected channel you are seeking does not appear, then begin turning the tuning wheel anti-clockwise until the station is found. It generally takes about twenty turns of the tuning wheel to cover the range of channels selected.
• When your selected channel appears on the TV screen, adjust the tuning wheel for the best picture and sound.
• Turn on the AFT and close the tuning drawer (or door).

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How to install your antenna

The following information about antennas is a guide to their installation. We suggests that a professional installers be called.

Choosing the right antenna

Outdoor antennas are preferred to the indoor variety whose performance can be affected by wall insulation, plumbing, electrical wiring, roofing materials and even people moving around a room.

Choice of an outdoor antenna depends on the channels in your area:

Very High Frequency (VHF)
• Band I antennas for channels 0 to 2
• Band II antennas for channels 3 to 5
• Band III antennas for channel 5A to 11
• Multi-channel VHF antennas for channels 0 to 11

Ultra High Frequency (UHF)
• 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 certain circumstances)

The UHF antenna size depends on how close you are to the transmitter. In most areas, where you can see the transmitting station, a yagi antenna with 8 to 10 elements or cross-pieces should be used.

At distances greater than 20km from the transmitter, or in difficult terrain, a 10 to 18 element antenna will be needed. This type of antenna, because of its length, may have to be mounted on a stronger mast.

In most locations, particularly where channels from both band 4 and band 5 are used, a phased array antenna is usually suitable.

Check with a reputable antenna installer for the correct antenna for your area.

Mounts or Masts
Numerous forms of mounting brackets are available for antennas. These can range from chimney brackets to fascia board mounts to free-standing masts for brackets to be bolted to the wall of your house.

Separate antennas for VHF and UHF signals are recommended. These can be mounted on the same post or mast, but always ensure that the UHF antenna is positioned about 1 meter above the VHF antenna.

Mount the antenna on the mast in such a way that it and the transmitter are in clear line of sight. It is usually best to mount an antenna on the side of the house closest to the transmitter.

Installation tips
When installing your antenna:

• Disconnect the power supply to your television set before starting any installation work.
• Ground your antenna mast electrically, using heavy gauge earthing wire"6mm" and a grounded rod. This will protect anyone who touches the antenna. It also offers your property some protection against lightening.
• Mount the antenna clear of power lines.
• The minimum height is the width of the antenna (above the roof line).
• Check local government regulations for mast heights if you are installing an antenna above your roof line.

Position your antenna
Generally you should point the antenna towards the transmitting station. And it is important that you have the antenna pointed at the correct signal source. For example, in some areas there is a main transmitter and a number of translators.

Shrubs and trees, building and hills in the direct path of your antenna may weaken the incoming signal and cause reception problems. If you cannot see the transmitting station, experiment by pointing the antenna in different directions-you may receive a stronger signal reflected off one of the obstacles mentioned above.

The antenna cross-pieces will need to be either vertical or horizontal, depending on the ‘polarisation’ of the transmission source.

Co-axial cable
Use low loss coaxial feeder cable to connect the antenna to the TV set. This type of cable is suitable for both VHF and UHF signals.

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. From the cable into a half-loop where it enters the house so that rainwater will drip off. Seal the entry point.

Connections
It is very important that proper coaxial connections are used at each end of the coaxial cable.

When connecting coaxial cable:

• Cut back the outer cover
• Cut back the center insulation
• Connect the center conductor cable to the antenna
• Ensure that the shielding braid is firmly contacting the saddle clamp, being careful not to crush the cable by over tightening the saddle clamp.
• Coaxial plugs and joints should be soldered or securely fastened with screw connections.

Antenna connection
Most antenna have a connector box where the coaxial cable is connected to the antenna. If yours does not have such a box, then a balun is required. This piece of equipment has a coaxial connection at one end and a ribbon at the other.

If your antenna needs a balun, connect the ribbon end to the antenna terminals, and the coaxial cable down lead to the coaxial connection. Position the antenna balun so that it won’t collect rainwater.

A balun will also be needed at the TV end of the cable if the TV has only ribbon-type connections. Connect the ribbon to the terminals on your set, and plug the coaxial into the balun.

Diplexer
A diplexer combines signals from VHF and UHF antennas into one output cable which can then be connected to your TV set. Diplexers can be mounted either near the antennas or near the TV.

You only need a diplexer when a TV set has just the one input socket for both VHF and UHF cables. Separate input sockets mean that a diplexer is unnecessary.

Splitter
More than one TV set can be connected to your outdoor antenna. A splitter takes an input signal from one cable and divides it between two or more outputs.

Amplifier
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.

FM rejection filters
FM broadcast signals can sometimes interfere with television signals and cause annoying patterns in the picture. The problem occurs where high level FM signals are present at the input of a television receiver.

This can often be solved by fitting an FM rejection filter to the receiver’s antenna input at the back of the television set. This filter is sometimes described as an FM trap.

The filter enables receivers to reject FM sound signals, thus preventing them from interfering with most television signals. However, they are unable to protect Band II channels (channels 3,4 and 5) because these television signals would be filtered out along with the unwanted FM radio signals.

Down converter
Older VHF-only TV sets will need a down converter to alter the UHF signal so that it can be used by the VHF set. Most video cassette recorders can used as a down converter. Check the manufacturer’s specifications of your VCR.

Master Antenna Systems "MATV"
Many hotels, apartment buildings, hospitals and office blocks provide wall-mounted antenna sockets which are connected by cable to a master antenna. A professional installer should do this work. Please ensure that the cable used for such connections is high quality coaxial cable.

If it is necessary to install an FM filter to such a system, it should be fitted between the receiving antenna and the first amplifier in the distribution system.