[amsat-bb] Tutorial on Working APRS Contacts on Kenwood TM-D710

[Robert Bruninga]

Here is what I was suggesting.  You keep an exchange in your status text
like this:

1D MDC QSL XXXXXX

And that is transmitted in each of your APRS position packets (which also
is displayed as a gridsquare on everyone's screens).  Each time you want to
QSL another contact you see in the STATIONLIST, you use the MENU button and
5 presses to then edit in the new call in place of the XXXXXX.  Press BCON
and wait for a response.

I am *not* a contester and have no idea if this constitutes a valid
exchange, but the 1D and MDC are my usual FIeld Day excahnge.  What would
be best for APRS use?

So, I receive a packet from station X, I send my QSL, he sees it and sends
his QSL.  Aren't excahnged grids and exchanged QSL's a valid contact?

No ACKS and only manually controlled retries.

If I am missing something, correct me, thanks
bob



On Sat, Apr 13, 2019 at 2:57 PM Clayton Coleman W5PFG via AMSAT-BB <
amsat-bb at amsat.org> wrote:

> Like many topics in the amateur radio world, there is a mix of what is
> prescribed in protocol versus how it's applied in the real world.
>
> Bob's right here. There are excess packets created by using APRS
> messaging vs a simple "one time" packet being sent as a UI.
>
> The weakness in using the built-in APRS functions of Kenwood, Yaesu, or
> other traditionally-terrestrial messaging systems is the load of 'waste'
> packets generated vs using a simple UI packet. The APRS messaging
> functions will often continue to transmit until they receive an
> acknowledgement. This can be problematic in a short-duration LEO
> satellite pass, especially when one station tries to message everyone in
> their HEARD list!
>
> Many people who operate solely with a radio such a Kenwood are oblivious
> to 'waste' packets being digipeated (repeat ACK's, REJ's, etc.)  Unless
> you're sitting at a terminal and viewing all the packets, your view of
> what is passing by is extremely limited; not just by the tiny display of
> your radio. For fun, I suggest running a terminal attached to your radio
> and monitor all packets at Field Day.
>
> I've observed passes when 10-15 stations were able to exchange packets
> and I've observed other passes when 2-3 struggled because one or two
> other stations were over-beaconing and sending messages repeatedly.
>
> It's like the many new stations incorrectly assuming the best way to be
> digipeated is to keep pressing BCON on their Kenwood radio until the
> glorious "MY POS" flashes and they hear a beep! OUCH. Those are
> typically people on omni antennas or in their car that have no idea
> they've been digipeated every time but their station is not hearing.
>
> Not everyone has the luxury of sitting in their shack to operate a
> packet/APRS-capable satellite. At home, I use UISS. By default UISS does
> not request acknowledgement or require it. It will only transmit a
> message or position packet upon pressing the appropriate function key.
> This helps limit the amount of "rapid-firing" typically employed by many
> of the folks using transceivers with built-in packet/APRS capabilities.
>
> Occasionally I like to make contacts via ISS or other satellites with
> packet digipeaters using either one of my Kenwood mobile or HT
> transceivers. Do I use the status text method? No. I use the MSG
> function like others on this thread have described. I keep it short and
> sweet.
>
> Do you want to strictly adhere to terrestrial protocol rules for
> acknowledging messages, often resulting in the logjam of packets, or do
> you want to increase efficiency and send the minimal frames necessary to
> get a clean exchange via satellite with another station? I leave that up
> to the operator.
>
> Have fun.
>
> 73
> Clayton
> W5PFG
>
>
> P.S. I think the unattended beacons remain my favorite nit-pick of
> packet/APRS satellites' use. :-)
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