[OZAPRS] Re: The Guide ....
vk3jfk at amsat.org
Thu May 27 15:39:28 EST 2004
Thanks for your input.
See comments below.
From: ozaprs-bounces at marconi.ics.mq.edu.au
[mailto:ozaprs-bounces at marconi.ics.mq.edu.au] On Behalf Of Terry Neumann
> >1. Do consider all other users of the HF network. Remember you are
> >sharing this single frequency with hundreds of other operators.
> I have no quarrel with the sentiment in this point. However, the
> "hundreds of other operators" worries me..... My MH list runs to about
> 5 or 6 stations most days. One day there might be "hundreds", but I
> don't think there ever will for reasons which are outside of this
> immediate consideration.
As we are talking of HF here we need to keep in mind the natural
characteristics of HF operations which means we have to think on an
international level for APRS operations on this frequency. Even if you
are not able to here (may be not able to decode) the other 101
(hundreds) operators they are on the same frequency as you are they may
be able to here your signal due to conditions or their super dooper
There have been several emails sent from US and European stations to
VK3MY providing signal reports for VK3MY-4 some of the stations that
have sent reports are not received by VK3MY-4.
> >1. Don't Digipeat any packets on HF (the only exception is for
> >your radio).
> >2. Don't transmit Home station positions on HF. Only Gates and
> >stations need to transmit position information.
> I think I know the reasons for this last point (2), but it certainly
> to defeat the purpose of the whole exercise. What is the point of
> transmitting at all if the position information is not given?
The main aim of APRS HF is to track moving objects. APRS was designed
to be a real-time tactical and emergency object tracking system. On HF
we are very limited in our data band width (through put) it is 1/4 of
the VHF band width with potentially a much much greater coverage area.
Why use this valuable band with to display boring objects that don't
move. As you state below your main interest is watching VK3BYD travel
around the country side.
> (I have similar concerns with earlier discussions which suggested that
> mobile stations shouldn't transmit speed and direction, but only
> position. Fact is that stations who are transmitting speed and
> direction in addition to position are getting their message through, and
> makes for much more interesting viewing).
I agree. Mobile HF stations should transmit there speed and direction
not only for entertainment but for safety reasons. If you use a TT3 or
HamHud this information can be sent in an APRS compressed format such as
MIC-E or APRS Compression, where it does not use any extra band with.
> This mode will never attract significant numbers of other users if we
> make it as interesting as we can whilst people who might be
> interested look in at the SWL stage.
I disagree, the main reason people will not use HF APRS is the lack of
a guaranteed Gate infrastructure where whey need it. People want to be
able to get their position on to the internet so that others be it
family or friends can see where they are and more importantly that they
are safe. HF APRS will provide good position information to families of
OutBack travellers via the internet (you don't have to be an amateur) if
we have a well designed and reliable Gate system.
>From experience I could not get many people interested in VHF APRS in
VK3 until I was able to establish a few digipeaters for people to use.
It's not much fun talking to yourself.
The 4WD HF radio network is very popular because it is guaranteed
reliable system that offers good services.
> It's about positions on a map at
> this early stage;
It sure is so why not get mobile on APRS HF?
> it's the next development beyond the MH list. At
> some point in the future perhaps perhaps we can filter down the amount
> info in our beacons, but surely not just yet.
> These are my own observations as one who is interested, doesn't always
> appreciate the finer points of the discussion, but remains interested -
> for the time being anyway. However if it wasn't for Warren's speed and
> heading information which I see on most days I probably wouldn't
> bother. Now I know that this last point is outside of those raised by
> Richard in his guide, but it's related by implication of earlier
> discussions, and the essential thrust of what is being reinforced by
> points in the guide.
> It's not easy writing a guide Richard; thanks for doing so. If the
> points I have raised bring out some constructive discussion I'll be more
> than satisfied.
Thanks for your input.
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