Licence Area Plan (LAP)

This is a Australian Communications and Media Authority (ACMA) term for a geographic area into which it allocates ABC, SBS, commercial and narrowcasting.


Transmitting to the whole potential audience in a Licence area.


Transmitting to part of the potential audience. This may be for a special interest such as Racing Radio, ethnic such as Chinese radio or community such as Twin Cities radio Wanneroo. The Chinese Association of WA is an applicant for a narrowcasting licence. Their submission wants Hamersley because it is close to the city and where the Chinese live.

Amplitude Modulation (AM)

This is the system which is in use at the Hamersley Towers. It is the oldest form of radio transmission. It is an analog system of the poorest sound quality but can cover large areas. Interference can be heard as if a radio sound.

Frequency Modulation (FM)

This system started in Perth around 25 years ago. Most of the transmitters are in the Hills. This system provides stereo sound in much better quality than AM. Coverage area restricted to the Perth Metropolitan area. Interference is inaudible on phones, and is an easily removed pattern on TV. The ABC Perth, uses FM for JJJ and ABC Classic FM and on 150 other FM transmitters.

Digital Radio Plus (DAB+)

This new system allows for multiple programs and additional data. This data can be used to transmit pictures, text etc. Coverage area is similar to FM.

Digital Radio Mondiale (DRM)

This is the newest system. It can produce FM like quality from an AM transmitter. This means that they could easily add it to the Hamersley Transmitters. If you get interference it will be a continuos buzzing sound in addition to any existing interference. On TV pictures it will add to the detail of lines, by adding dots on additional lines. However, following submissions by RIGHT, ACMA have announced this technology will be transmitted from the South West instead of Hamersley.

Analog TV

This is used by ABW 2 (ABC), TVW 7, STW 9 NEW 10 and SBS 28. AM interference produces patterns on the picture.

Digital TV (DVB-T)

This is used by ABW 12 (ABC), TVW6, STW8, NEW 11, and SBS 29. Interference can cause pixelation and sound chirps and silence. In severe cases a “No Signal” sign will appear. Insufficient or excessive TV signal strength can also cause these effects.


The digital TV picture breaks up into blocks.

Set Top Box (STB)

It is a digital TV receiver, without a screen or speakers.

Video Cassette

Interference generally occurs on playback and can occur on record. Generally a coarse coloured wavy pattern is produced. If the recording is from the videocassette recorder’s receiver all of the analog TV interference will be added.

Cyclomotive Force (CMF) - Signal strength as defined below.

The number of volts from an antenna of 1 metre in length. It is to be located 1 km from the transmitting antenna, 10 m above the ground. It should occur at 50% of locations at that distance for 50% of the time.

Distorted Sound

It sounds fuzzy and may also have sibilance on the letter ‘S’. This usually occurs from overloading.

Muffled Sound

This is a lack of high pitched sounds. This is occurs in nearly all AM receivers.

Dial Up Internet.

This is the use of a standard phone line to communication between computers. This is usually a maximum of 56 kBit/s


This is the use of as phone line to not only connect a telephone to the exchange and in addition a much faster data communications to an Internet Service Provider.

Asymmetric Digital Subscriber Line (ADSL)

The technical name for the most common broadband (fast) internet access used in Australia.

Band 2

TV channels 3, 4, & 5. Channels 3 & 5 are used in Bunbury. FM radio band covers part of TV channel 3 and all of channels 4 & 5.

FM Band

The FM band is covered by TV channel 3 – 5. It consists of 100 FM radio channels. In one licence area you can only allocate 25 channels. Since SSW 3 (GWN) and ABSW 5 (ABC) Collie are in the FM band these leaves 11 clear high powered channels.


The study of the geographical incidence of disease to find a cause. It uses a statistical approach.