Background
In the early 1980s, the Aboriginal communities and non-indigenous populations
in the outback areas of the Northern Territory had been vigorously advocating for improvements to the existing regional radio
broadcasting services available in their region.
Consequently, in 1985, the Australian and Northern Territory Governments, and
the ABC, established shortwave services from three new transmitters located at
Alice Springs, Tennant Creek, and Katherine, carrying relays of ABC and other programming originating from Alice Springs and
Darwin.
These
SW transmitters use vertical-incidence antenna configurations, known as "shower propagation", intended to limit low-angle
long-distance propagation.
The
primary service area is radially 500 km to 600 km.
The
initial schedule, which survives to the present time, was for 24-hr broadcasting,. using frequencies in the 2 MHz (120 metre)band
during the night, and on 5 MHz (60 metres) during daytime.
The
transmitters are not staffed, and the changeover from day to night channels is done automatically.
The
original installations were actually 100 kW, but output is limited to 50 kW.
Responsibility
for technical management of these facilities is undertaken by Broadcast Australia, the National transmission carrier, under contract from the ABC.