South Australian Amateur Repeaters
Download a map of the SA repeaters.
A Radio Repeater is a combination of a radio receiver and a radio transmitter that receives a weak or low-level signal and retransmits it at a higher level or higher power, so that the signal can cover longer distances without degradation.
In many communities, the repeater has become the on-the-air gathering spot for the local amateur radio community.
Repeaters are typically maintained by clubs or groups of amateur radio operators. In some areas multiple repeaters are linked together to form a wide-coverage network, such as the linked system provided by the South East Radio Group which covers most of the South East of South Australia.
Repeaters may also be connected over the internet.
Echolink allows computers to connect to repeaters anywhere around the world and the Internet Radio Linking Project (IRLP) also allows for direct repeater linking throughout the word.
In addition, communications satellites called OSCARs have been launched with the specific purpose of operating as spaceborne amateur repeaters.
SRAG have two UHF repeaters which can be used as stand alone units or linked together as described below.
“Rpt South” and “Rpt North” are identical in configuration. Two Tait TM8110 transceivers, one as a transmitter and one as a receiver.
Each repeater operates as a stand alone unit. A user has to select which repeater to use by selecting “Rpt South” or “Rpt North” on their radio.
The “Link” is a Tait TM8110 which receives on the “Rpt North” output frequency and transmits on “Rpt North” input frequency via the beam antenna.
The “Link” radio is controlled by the “Audio Bridge”.
The “Audio Bridge” is by Omnitronics (type 619EI). As the name implies, the audio bridge connects and controls the audio between the “Link” radio and the “Rpt South” radios.
- ‘User 1’ is using “Rpt North” and ‘User 2’ is using “Rpt South”
- ‘User 1’ transmits. The “Link” receives the output of “Rpt North” and passes the audio via the “Audio Bridge” to the “Rpt South” transmitter
- ‘User 2’ transmits. The “Link” receives the receiver audio from “Rpt South” via the “Audio Bridge” and transmits on the “Rpt North” input frequency
Photo of the repeater box containing the audio bridge, Rpt South (one transmitter and one receiver) and the Link radio.
The Yaesu FT-8100 VHF/UHF radio is designed primarily for mobile use, but can be used as a translator between VHF and UHF.
The radio is usually placed on a hill with two antennas - one for each frequency. A vertical VHF antenna and a UHF beam antenna with the beam pointing towards the command caravan is the usual setup.
If someone transmits on VHF, the signal is received by the FT-8100 and retransmitted on UHF where the signal is received at the command caravan.
If the command caravan transmits on UHF the signal is received by the Yaesu FT-8100 and retransmitted on VHF.