[amsat-bb] ISS APRS with an HT

[Scott]

Hi Brian & everyone.

Websites like ARISS.net monitor the APRS traffic and display a list of
packets that match certain criteria.  In the case of a site that wants to
display packets digipeated via the ISS, they're looking for "RS0ISS*",
which is appended to the digipeat path of a packet that is relayed thru the
ISS.

When it works correctly, you transmit a packet that is digipeated by the
ISS and the digipeat from the ISS is heard by an iGate that puts it onto
the internet for sites like ARISS.net to display.

However, generally speaking, the APRS network is designed to toss out
"duplicate" packets.  And as you might imagine, it's
first-come-first-served.

If you'll notice on the following link to a screen shot:

https://www.qsl.net/k/k4kdr//images/KO4AQF-digipeats.png

... the vast majority of your packets are being heard DIRECTLY by in iGate
run by W4GCW.  So, a good portion of the time, when you get digipeated via
the ISS, the APRS network considers that a duplicate and it's discarded.
YOU (and others) might hear it off the air, but it'll never show up online
anywhere.

In the same image you can contrast those locally heard packets with packets
that were digipeated & uploaded by iGate's KE4AZZ-3 & KC5ILO-12... of
course that's how it's supposed to work.

You might want to reach out to W4GCW to see if he'll filter out your call
sign on his iGate to give your digipeated packets a chance to be heard by
an iGate and get forwarded onto the greater APRS network as DIGIPEATS
(instead of being discarded as duplicates).

-Scott,  K4KDR

==========================

On Wed, Mar 25, 2020 at 7:30 PM Brian Wilkins KO4AQF via AMSAT-BB <
amsat-bb at amsat.org> wrote:

> I had no issue until it went offline and then came back. I believe one of
> the iGates near me may have went offline since the ISS APRS pause as ISS is
> confirming my messages however nothing is showing up on ariss.net and I
> can
> exchange messages with others. I am considering building my own APRS RX
> iGate from an RTLSDR and Raspberry Pi just to digipeat my own packers back
> to APRS.fi website
>
> On Wed, Mar 25, 2020 at 7:22 PM John Brier via AMSAT-BB <
> amsat-bb at amsat.org>
> wrote:
>
> > I got through it on March 21st on a 12 degree pass using a TH-D72 and an
> > Arrow:
> >
> > https://twitter.com/SpaceComms1/status/1241598936814694400?s=19
> >
> > It was hard, as I believe it is a little deaf or not decoding
> consistently
> > based on past reports. Some have said it seems to be easier with Kenwood
> > radios.
> >
> > They are sending up a new Kenwood radio system soon that supports
> > digipeater ops so don't dismiss this mode entirely!
> >
> > 73' John Brier KG4AKV
> >
> > On Wed, Mar 25, 2020, 19:02 Steve Kristoff via AMSAT-BB <
> > amsat-bb at amsat.org>
> > wrote:
> >
> > >
> > >  Has anyone been able to digipeat APRS through the ISS with a 5 watt HT
> > > and an Arrow antenna lately? If so, what are your secrets for success?
> > > If 5 watts and an Arrow doesn't work please let me know that, too, so I
> > > can pursue a different aspect of our hobby.
> > > thanks!
> > > Steve AI9IN
> > > Grid EM79ji
> > > Oldenburg IN 47036
> > >
> > > _______________________________________________
>
>
>