Aerials

Aerials for Radio and Television

Many people still use tuners in their hifi systems and to obtain the best possible quality of broadcast sound, a good quality aerial must be used. Many tuners come with small aerials to sit on top but these are generally not very good unless you are in a very good reception area. A proper external aerial is the best. Many existing TV aerials can be adapted by having an FM splitter attached. It is also crucial that the aerial be maintained as both TV and FM reception can be affected and weakened. Make sure no pesky birds have broken any of the rods and that no corrosion has formed between crucial electrical contacts.

It is best to obtain qualified help as crawling around the roof can be very risky. A proper aerial technician will have equipment to measure signal strength and can align the aerial for the best signal. You may even be able to tell them which station you watch the most as some transmitters are located in somewhat different locations.

If you are using an internal antenna, reception will not be as good as with an external aerial and is more susceptible to interference. This is because the signal is partly obstructed by the house itself and of course anything inside the building, such as metal objects / whitegoods, electrical wiring and metal grilles. Move the aerial around to see if a better signal can be obtained. AM often can be received with just a length of wire, again try different positions.

FM reception can be limited to distances of 50-100 kilometres depending on the terrain. The signal effectively travels in a straight line and hills and tall buildings can affect reception. AM signals travel much further, but because of the nature of how AM transmission works, it is more susceptible to interference. Interference is cause by many things including power lines, electrical machinery and even lightning. Radios equipped with AM stereo are even more prone to interference, but not much is broadcast in AM stereo anymore. FM stereo is of course what we are mainly interested in and a little known fact is many tuners will reduce the stereo separation, as the signal gets weaker.

If you live near a transmitting tower, you may suffer from signal overload. Signal attenuators are available which can plug inline with the aerial cables to reduce the signal and help reduce the overloading. Aerial size needs to be chosen to suit your particular distance from the transmitter; too big an aerial too close will cause overloading as the signal gain can be excessively high.
Many types of aerials and accessories are available from your local electronics store, ranging from external aerials, indoor and amplified aerials, boosters, attenuators, splitters and of course cables. Choose good quality cables especially for long runs as they will allow more of the signal to pass through while reducing the amount of interference. Proper crimping or soldering tools are required to make your own cables, so check what is needed before commencing any wiring.

With free to air and paid TV becoming more popular, the reception of these is important as well. For free to air TV the same tips above still apply. It is common to have two TV aerials, ever since SBS began broadcasting, UHF (ultra high frequency) has become more popular and can actually have a better signal than the older VHF (very high frequency) signals. Often both types of aerial are combined into one with both signals combined at the masthead. You may want to try tuning your favourite TV stations on UHF and you may find a better picture is the result.

In some locations you can actually pick up several sets of TV broadcasts, sometimes for example the main capital city stations and the regional stations as well. Since they are usually coming from different locations you may not have been aware of this and second aerial would be required to receive both. Again you local aerial company should know if it is possible in your area. While they often broadcast the same shows, there are occasions when the programming is completely different.

Pay TV is delivered either by a cable or by a satellite dish. The providers generally supply, install and maintain this equipment as you only “rent” it from them. Some pay TV boxes actually allow you to check the signal strength of the satellite signal, check the menu or user manual for more information. Sometimes the signal can be lost of there is strong cloud cover which will block the signal from the satellite. If you regularly loose the signal or have a lot of glitches, you should report it to the provider. They will give advice over the phone on what to check and send a technician if required.

With all types of TV and radio you should use the best quality signal feed you can, such a S-Video or digital for the audio if available. Coupled with an AV-Received or decoder, you can get quite good quality sound; some pay TV services broadcast digital surround sound for selected movies. You probably don’t need to use the best cables possible for these types of connections as the quality of the source often isn’t as good as DVD or audio discs, but make sure they still match the quality of the components you have.

Written by Leon Gross, originally published in Audio & Video Lifestyle magazine.