Transmitter information

About transmitters

The transmitter information presented in this search facility is derived from the ACMA's records of licensed broadcasting transmitters. The inclusion of a transmitter in the search results indicates the existence of a transmitter licence for the service, however it does not guarantee that the particular transmitter is operating. While every effort has been made to ensure the accuracy of the transmitter information presented, the ACMA cannot guarantee the information to be free from errors.

When comparing transmitter locations with other spatial data such as satellite imagery or GIS topographic data, discrepancies will inevitably be encountered. These discrepancies are usually the result of accuracy limitations in the acquisition and/or presentation of the spatial data.

The positional accuracy of spatial data, including satellite imagery such as that available via Google Earth and Google Maps, may be subject to considerable variation due to limitations in acquisition, processing and display of the data.

Forms of transmitter list

The transmitter list for a broadcaster presented by this search facility is available in several forms.

Basic

This is the web page returned when a broadcaster's callsign link is selected from the initial postcode or place name search query. Only the most basic information about each transmitter is included.

Advanced

The advanced forms of the transmitter list are not displayed as web pages but are presented as links to data in alternative formats appropriate for use in different applications or for graphical display:

These links are included on the web page returned when a broadcaster's callsign link is selected from the initial postcode or place name search query.

Basic information

The following information about transmitters is included in all forms of the transmitter list for a broadcaster:

Area served

A descriptive name for the geographic area in which the transmitter's signal is intended to be received.

Mode

For television services, whether the transmission is analog or digital; for radio services, whether the transmission is AM or FM.

In the basic transmitter list, the mode is conveyed by colour coding of the background of the list item, with a colour key at the top of the list.

In the CSV file, the mode is identified textually, being one of "Analog TV", "Digital TV", "AM Radio" or "FM Radio".

In the Google Earth Placemark form of the transmitter list, and when the transmitter list is viewed in Google Maps, transmitter icons are colour coded as follows:

      Analog TV 
      Digital TV 
      both Analog TV and Digital TV 
      AM Radio 
      FM Radio 

Channel

The identifier used to refer to the part of the radio-frequency spectrum used for transmitting a television service.

Frequency

The frequency of a radio service, expressed in megahertz (MHz) for FM radio services and kilohertz (kHz) for AM radio services.

Polarisation

The polarisation of the transmitted signal depends on the configuration of the transmit antenna's radiating elements. The recognised types of polarisation are:

Television services normally transmit with either horizontal or vertical polarisation, though several dual polarisation services exist for implementation reasons. FM radio services normally transmit with either mixed or vertical polarisation, although horizontal polarisation is occasionally used for implementation reasons. AM radio services always transmit with vertical polarisation.

Antennas used for domestic reception nearly always receive in only one plane of polarisation, and the antenna elements should be oriented to match the transmitted polarisation.

For radio services, polarisation is not displayed in the basic transmitter list as in most circumstances reception of these services does not require consideration of the antenna's orientation. It is included in the advanced forms of the transmitter list as a matter of technical correctness.

Site

A description of the transmitter's location.

Advanced information

The following additional information about transmitters is included in the advanced forms of the transmitter list:

Carrier frequency

The value, in Hertz, of:

Frequency offsets from the nominal carrier or centre frequency are used for some services to improve reception in the presence of other services with certain frequency relationships to the wanted service. Any applicable frequency offset will be included in this value.

Power

For AM radio services, the transmitter power is listed. For FM radio and television services, the Effective Radiated Power (ERP) is listed.

Pattern

The type of radiation pattern used by the transmitter:

Antenna height

The maximum height above ground level, from the base of the mast or tower, of:

Site coordinates

The geographic coordinates (longitude, latitude) of the transmitter's location are in decimal degrees, referred to the GDA94 datum. Coordinates in Google Earth Placemark files are referred to the WGS84 datum, however as the discrepancy between GDA94 coordinates and WGS84 coordinates is currently less than 1 metre, the GDA94 coordinates are used directly.

Standby transmitters

Some broadcasters maintain standby transmitters at alternate transmitter sites, which are included in some other ACMA publications. Standby transmitters are not normally included in these transmitter lists.

Day/Night switching of AM services

Some AM radio services operate with different antenna radiation patterns and transmitter powers depending on whether it is day-time or night-time, to improve reception during the day and minimise interference during the night. Only the day-time operating parameters are shown in these transmitter lists.