TMR Network Image: infocux Technologies




TMR Network




 

Tas Maritime Radio monitors and broadcasts on VHF and HF frequencies.

Most of our work is done with small vessels on VHF. HF is more likely to be fitted to larger vessels on long voyages.

The VHF network

 

VHF coverage map
Image: Brian Muir

This coverage map shows locations from which you should be able to communicate with us on VHF. The higher your antenna is mounted, the greater your VHF range (remember that VHF is largely line-of-sight). Most VHF bases are located on hills or mountain tops.

 

The pink dots on the map indicate the location of the bases and the highlighted circles the coverage areas. There's quite a bit of coverage overlap which is why we ask you to change to different channels for skeds (69 for North East and North West Coast, 68 for Flinders Island, Maria Island and Mt Read, and 67 for Mt Mangana, Elliot Range and the Central North Coast.

The extreme south is covered by the channel 82 repeater on Maatsuyker Island (the yellow dot).

Tas Maritime Radio operates the Three Hummock (North West Coast) base only when Smithton Radio operator Mary Kay is unavailable.

Tas Maritime operates the North Coast base as an adjunct to Tamar Sea Rescue.

All bases are monitored by TasPorts Security on behalf of TMR from 1930 - 0700 hours for urgent calls only.

 

HF Radio

The blue dots indicate HF installations. The installation on Bruny Island utilises three fixed receivers tuned to the 4,6,& 8 mHz distress frequencies, while a high power transceiver is connected to a 40 metre vertical antenna. Snug Tiers has backup HF receiving capability and 2 high powered transmitters.

 

VHF station map
Image: Brian Muir

HF radio waves reflect from the ionosphere which makes HF very susceptible to many factors (day/night, solar activity etc) and can suffer from more interference than VHF, but the rule of thumb is a higher frequency for greater range. We regularly hear Taupo Maritime Radio from New Zealand and assist them at times with relays to vessels. Vessels on long voyages can usually communicate with us well into the South Pacific and all the way to New Zealand. Often we provide vessels with radio checks in NSW, Victoria and SA – and have even picked up the US Coast Guard installation from Kodiak Alaska.

 

 

Linking the Bases

The map to the right shows how we link the bases. All links are radio links, either digital or analogue, and link through the link hub at Mt Nelson.

The VHF automated weather service is computer-generated by the weather bureau and downloaded to a computer and fed via a link to the transmitter at Snug Tiers.