[OZAPRS] Was Byonics, Australian requirements

David Hopkins davhop at bigpond.net.au
Tue Aug 7 08:50:09 EST 2007

Over the last week or so there has been a flurry of emails on the 
subject of a commercial tracker from the USA.

Most people seem to be of the opinion that it is of limited use 
because there is no receiver in the unit.

Perhaps we should go back to square one and come up with the 
requirements for a APRS setup that suits Australian conditions and 
then look at how we achieve this outcome.

I would like to start a discussion from observations I have made over 
the last couple of years. Note these mainly centre on Brisbane with 
the occasional trip to Sydney via the New England Highway.

As I see it three designs should cover the average operators requirements.

1.                  A dual frequency transceiver for the vehicle.
2.                  A transceiver that can be used as a digi
3.                  A receive only setup to feed the data into the

Item one need not be an expensive commercial transceiver. The Maxom 
surplus radios have filled this requirement on many occasions at a 
very affordable price. However their availability is drying up and 
hence the prices are increasing. Another observation locally is that 
the output power is inadequate. While using one of these barefoot I 
rarely made it into the local repeaters unless I was a couple of 
kilometers from them. Even when using the Kenwood D700 at 50 watts 
there are a considerable number of areas that it is difficult to be 
received from.

It appears, in Brisbane anyway, one should  run about 30 watts for 
decent coverage.

Item two. With little modification of the transceiver used for mobile 
use it can be pressed into service as a digi where required.

Item three. One doesn't require a transmitter to input data to the 
Internet. As I see it is perhaps a uni-directional aerial with 
perhaps a preamp at the top of a mast. A single channel receiver, tnc 
and a computer with a 24 hour Internet connection.

One of the greatest deficiencies as I see it is coverage of the 
network. As an example take a trip from Brisbane to Sydney via the 
New England Highway. There is excellent coverage from Brisbane to 
Cunningham's Gap a distance of about 80Km. There the coverage 
promptly cuts out and does not reappear until north of Maitland just 
north of Newcastle. While the space station was in operation one 
could get a couple of position reports out but this was next to 
useless. There are quite a number of large towns along the highway. 
Imagine if these towns had a receive only station feeding the data 
into the Internet, coverage would be greatly increased at minimal cost.

Another advantage of the receive only station is that no licence fees 
have to be paid. It would be nice if the PC could be eliminated in 
receive only stations to minimize running costs and tying up an 
expensive computer.

The above is a very brief overview and certainly short on detail. It 
is written in order to get discussion going and perhaps motivate the 
APRS community into action without relying on equipment from the USA. 
Surely we have people in this country with expertise in the fields 
required to develop our own solutions in a brilliant amateur radio

Gentlemen your words of wisdom please.

David G. Hopkins (Vk4ZF)
S27 32.191 E153 11.867 

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