Travellers Net experiment

A week of experimentation is planned for the new HF IRLP node 6801 in Darwin. Mike (VK8ZMA) & Rex (VK8RH) in conjunction with Peter (VK6HH) and Roy (VK6BO) plan to test the new node's ability to handle real life HF activity in an effort to refine any issues that remain.

As a frequent listener for many years and recent user since January this year, when HF privileges were extended to "Z" calls, Mike had pondered the problems of communication while touring the vast array of Aboriginal Communities in the Top End of Australia with his employment.

Back in Darwin there was a perfectly good IRLP/EchoLink node, but of course as it was on 2 Metres and its range was very limited. In conjunction with Rex we started looking at all the issues of DTMF on HF SSB, an effective squelching system, etc. This was some 12 months ago and the first
experiments were with an old Codan 7727, much modified and running on Node 6800 for a few hours a day while I went out bush and tested the system. Suffice it to say that many months and thousands of Kms later we felt ready to go with the prototype HF only node.

So node 6801 was born and sports an IC706 which is programmed by the Linux node PC to change frequencies at various times of the day. Full details of Rex's Node can be found at his website http://vk8rh.zapto.org
The system runs 100 watts into a broadband dipole, 24 hours a day.

The very much modified Codan style squelch system is going to have some further work done on it by Rex, but in general it works well and keeps the extraneous rubbish to a minimum. A lot of work has been done on the PTT circuitry to eliminate pulse back on the node as well.

So now we look to a practical test for the system and that is where the Travellers Net comes in. We wanted a source of HF traffic spread wide and during November for 5 days we are going to connect Node 6801 up to reflector 9506 in Sydney from 0255z until 0330z on the Travellers Net on 14.116 MHz

Peter and Roy are aware of this and while supportive of the experiment have asked that amateurs only join in and talk if it is specifically related to matters involving travel or the tests when they are clear of all normal traffic. We will be monitoring and have agreed with the guys that if it interferes with their normal daily operation we will terminate the connection immediately.

After the week is up we will assess the experiment. This could also work equally as well with the 21.185 Travellers Net or any other Net situation where a HF component could be useful.

One of the objects of the exercise is to continue experimenting with various types of nodes and my next plan is to install a node in a laptop with a view to a portable node for either HF or VHF as broadband connections are becoming more readily available around the country (and
the world for that matter).

Any feedback on the project is welcome to either Rex or myself:

Mike VK8ZMA oziemike@yahoo.com

Rex VK8RH webmaster@bom.twp.arm.gov

One word of warning. As the transmissions from Node 6801 in this case will be on 20 Metres, make sure your licence conditions permit you to transmit there even though your originating signal may be on 2 metres. The onus is on you ultimately to keep it legal. Node 6801 does transmit on Novice bands at other times of the day and the schedule for these can be seen at the website mentioned earlier.

Our thanks go out to Roy and Peter for letting us try out the system in conjunction with the Australian Travellers Net who have provided such an invaluable service to the touring Australian Amateur's for so many years.

Mike VK8ZMA

Source: Wireless Institute of Australia

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