Single Dwelling
What is involved in the conversion process?
A typical household TV system, illustrated in Figure 1, will normally consist of an antenna, cabling, wallplates and flyleads leading to the digital reception equipment (e.g. TV, set-top box). Problems with receiving digital services may occur in one or more parts of the system. For example, reception of some or all of the new digital channels via the existing antenna might be marginal and/or the cabling may not carry the digital signal effectively. In such cases replacement needs to be considered.
An initial assessment should be made of each part of the existing system to find out whether an upgrade is required. The level of upgrading necessary will vary depending on what equipment is used in the existing installation. There is no need to upgrade antenna systems or cabling to receive High Definition (HD) digital signals if the dwelling receives Standard Definition (SD) digital signals clearly.
To get the benefits of the extra program channels and clearer pictures from the digital broadcasts, there may be costs associated with upgrading the receiving system for digital FTA TV. These may include:
- upgrading the rooftop antenna/aerial;
- installation of new shielded cabling; and
- labour costs associated with the design and/or installation of the above.
Note that if the dwelling is located in a weak signal area and/or multiple outlets are required around the house, a high gain antenna may not be sufficient and new amplifiers may be required. Professional installers should take signal measurements during the assessment to determine if amplifiers are required.
It is important to determine if the current TV antenna/aerial is designed for the same band of operation that the digital TV broadcasts in the area will be transmitted on. In most cases the antenna is likely to be suitable for digital services. In some cases there will be a need to upgrade the antenna either because the new digital channels are in a new frequency band or because the antenna is older or in disrepair and is unlikely to receive adequate signal levels due to that disrepair. Refer to Appendix D for further information about antennas.
Once it is established that the antenna is of a suitable type and is in good repair, it is important to determine whether the digital TV signals are distributed to each TV wallplate outlet at a sufficient level and without interference. Some detailed information on these measurements is contained in the section titled ‘Measuring Signal Strength’.
Some installations, especially in larger single dwellings, may use equipment such as channel converters, amplifiers and splitters that were only designed to cater for the reception of analog services and may not meet the requirements necessary for digital FTA TV reception. For example, for a small distribution system installed for analog TV, the installer may have shifted some analog TV channels to different channels to avoid nearby interference issues or reduce ghosting. Those channels selected could now be a channel used for digital TV transmissions.
Poor performance can be due to a number of factors including low received signal level at the receiver or the ingress of interference into the installed system. In some circumstances it is appropriate to replace the existing cabling with more modern, better shielded coaxial cable
suitable for digital TV reception. Cabling will need to be replaced if there is a loss of signal quality or level that occurs as the signal travels from the antenna to the wallplate.
Once the dwelling’s system has been assessed and possibly upgraded to access digi
