[OZAPRS] Was Byonics, Australian requirements
David Hopkins
davhop at bigpond.net.au
Tue Aug 7 08:50:09 EST 2007
Gentlemen,
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
Internet.
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
activity.
Gentlemen your words of wisdom please.
David G. Hopkins (Vk4ZF)
CAPALABA QLD.
AUSTRALIA
S27 32.191 E153 11.867
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