[OZAPRS] Australian requirements

Norm VK3XCI vk3xci at aanet.com.au
Thu Aug 9 08:51:46 EST 2007


I think there may be a number of "us" entertaining similar thoughts!

In brief... a dedicated single channel "handy" set up specifically for 
APRS. The Rx need not be super sensitive, 2.5uv would suffice, nor need 
it be extremely selective, since it's part in the order of things is 
simply to avoid txing over someone else.

A transmitter is easy. the receiver maybe not so. I've been out of the 
commercial RF side for too long to know what is around, but I'm sure 
I've seen a one chip FM receiver somewhere.


David Hopkins wrote:
> Gentlemen,
> My earlier posting caused a flurry of activity on the group but 
> I  think it got a little of the intended track.
>  From some of the comments I gleamed the following.
> If you have a four wheel drive and go out in the sticks there is no 
> alternative but to use HF. No Argument!
> However 99% of the APRS users in this country only travel in the city 
> with short trips into the surrounding countryside and very occasional 
> travel between capital cities on established highways.
> I doubt if anyone would want to use HF in these situations. Imagine 
> the traffic on the channel at 300 baud.
> So back to the original intention of the posting.
> How do we get equipment to use that is small, efficient  and reasonable
> Someone suggested the $99 transceivers available locally and made in 
> China. Good idea however it becomes a bit unwieldy hanging wires out 
> the back and adding external circuitry to make it all work. While 
> this is a quick fix I would like to think we could do better.
> As an example consider the family car (not a 4X4). If one had a small 
> box that contained a custom designed single channel receiver and 
> transmitter with an aerial connection, a GPS input and a DC input. 
> This could be mounted in the boot and the only tell tail signs that 
> the installation existed would be the whip antenna. If this was 
> mounted on the windscreen glass it would be disguised for a mobile 
> phone setup. The GPS can be placed on the parcel shelf behind the 
> back seat and covered with a hat.
> The radio would be powered up only when the ignition is turned on.
> I see this having several advantages. You don't have to worry about 
> turning it on and off and therefore no flat batteries when you least
expect it.
> If the car is stolen you can watch it being driven away and the thief 
> won't know its being tracked.
> The above would be a argument for an Australian design project to get 
> more people involved in the hobby.
> What do others think?
> What specifications would be required?
> Once we got something like this nutted out we could look at 
> increasing the repeater coverage. Possibly using a version of the car
> David
> David G. Hopkins (Vk4ZF)
> S27 32.191 E153 11.867 

Norm, VK3XCI,
Mildura, The Wintersun City

Victoria, Australia.
Ozaprs mailing list
Ozaprs at aprs.net.au

More information about the Ozaprs mailing list