[aprssig] 6M APRS via meteor scatter forum?
Ev Tupis
w2ev at yahoo.com
Sun Oct 15 22:09:15 EDT 2017
Hi Ron,
Think of MS as E-layer propagation that lasts only as long as the ionization level permits for the frequency being used. There is nothing magical about MS. The geometry is exactly the same as E-layer communication (with an added "Doppler" factor).
If a station is has problems utilizing E-layer propagation (poor horizon, etc.), then it will have problems with MS.
Though I have some experience, satellite is not my forte'. However it seems to me that a traditional satellite-based, store-and-forward messaging system is well suited for your use-case. LEO Amateur satellites orbit below the Van Allen belts and tend to be less suceptible to the X-ray events that impact geostationary birds.
Best regards,Ev, W2EV
On Sunday, October 15, 2017, 5:00:26 PM EDT, Ron VE8RT <ve8rt at yknwt.ca> wrote:
Ok part 2 :-)
I like the questions.
The end goal is minimal emcomm capability that doesn't rely on HF
propagation. Satellite is a good prospect and would probably be the
first choice. But a serious X-ray event could interrupt that, we had
another event several years back with a commercial satellite that put
commercial, government, and military communications out in the eastern
Canadian arctic for hours.
I'm not a DXer in the sense that I haven't any interest in getting
DXCC, it would be for personal satisfaction only.
So at this point this is experimental to find out, would it work, how
well would it work, how simple can an effective station be, would it
work from a location with a poor horizon (mountain valley), could it
handle some basic health and welfare traffic (not time critical). Does
it need to be APRS, no I don't think so, but I like the idea of the
traffic reaching a point where it could be seen online.
I'm not open to suggestions, I'm practically begging for ideas :-)
Ron VE8RT
On Sun, 15 Oct 2017 19:48:15 +0000 (UTC)
Ev Tupis <w2ev at yahoo.com> wrote:
> In the "old days" I used to tune to TV channel 3. It was absent of any local station. When it lit up, I'd call "CQ Scatter". I worked many states that way.
> To my knowledge, nobody has come up with a self-triggering mechanism using a broadcast source as you suggest.
> The footprint of the distant point is proportional to the frequency used. If using a broadcast FM station (the "3 meter band") as your "trigger", you can be certain that a 6 meter signals' footprint exists along the same path...and it is actually a bit more broad at the DX end.
> The requirement of high duty cycle is based on leveraging the time-domain as explained earlier in the thread.
> You have introduced the concept of an IGate station. Traditionally, APRS MS operation takes place without an IGate involved, so I'm unsure what role you see for it.
> If your intent is EmComm, then there are much better ways to go about the task.
> So...what is your purpose? Experiment? EmComm? DXing? etc.?
> Cheers,Ev, W2EV
>
> On Sunday, October 15, 2017, 9:52:24 AM EDT, Ron VE8RT <ve8rt at yknwt.ca> wrote:
>
> Ooooh! Stupid simple idea just came to mind for emcomm APRS.
>
> Assumption 1, the destination city for the emcomm traffic has
> working high power FM broadcast stations on air.
>
> Assumption 2, a MS path for the FM station between the originating
> station and the destination station is also a working path for the 6M
> traffic.
>
> If both are true then there is no need for high duty cycle
> transmissions to determine if a path exists, a separate receiver tuned
> to the destination FM transmitter could trigger a data exchange.
>
> A question though is how small is the MS path footprint, how close
> does the igate station need to be to the FM station used?
>
> Ron VE8RT
>
> On Sun, 15 Oct 2017 11:11:21 +0000 (UTC)
> Ev Tupis <w2ev at yahoo.com> wrote:
>
> > Hi Ron,If you are interested in specifically using APRS for MS on 6 meters, you will need to setup both ends of the path, just as you have done. There is little-to-no 6 meter APRS activity on 6 meters to use as a "base".
> > Operation requires a transceiver and/or amplifier that is capable of 50% duty cycle (use a Fan!). One station will TX for 15 seconds while the other one RX's. Clearly, you must coordinate TX and RX intervals.
> >
> > The more power you transmit, the easier it is to make a contact (a general principle that transcends MS-specific communication).
> > Some degree of success has been had with as little as 25 watts + 10 dBi antenna (250 watts EIRP) at 6 meters.
> > Success is largely defined within the "time dimension" (being able to operate for long periods of time). Since everything is computer controlled, it is possible to select a seldom used frequency and let it run over night...taking advantage of the spike in MS ionization that occurs from 3 AM to 9 AM local time. This works well if you are allowed to run under "automatic control" (like an FM repeater does) rather than being forced to have a human operator present at all time.
> >
> > FM APRS works well. So does the SSB mode. You can experiment to see which provides a superior experience.
> > 'hope this has helped as a bit of a primer.
> >
> > Best regards,Ev, W2EV
> >
> > On Saturday, October 14, 2017, 8:21:12 PM EDT, Ron VE8RT <ve8rt at yknwt.ca> wrote:
> >
> > Hi,
> >
> > I've re-joined the APRS SIG forum.
> >
> > And I'm doing a little shopping for 6M gear. I have a FT 726 that
> > is being shipped to me from the US, Joel at RF Connection offered it to
> > me for free, along with additional modules, and manuals, for the cost
> > of shipping. And I have a new in the box Cushcraft 5el yagi thats been
> > in the back shed since I bought it. With short coax run up the tower I
> > should be fine without a masthead preamp.
> >
> > The National APRS Meteorscatter test that Bob mentioned would be
> > interesting to look at. Of particular interest is the useable range,
> > we need a thousand kilometres to get into Edmonton from here, the
> > closest major city. This part of the Northwest Territories is
> > relatively flat, the Yukon on the other hand is mountainous and I'd
> > like to know how well this would work in the mountain valleys.
> >
> > Yuuri, VY1YU / JS6SHS, who ran the earlier HF propagation
> > experiments has been e-mailed to see if he'd be interested in trying a
> > MS APRS experiment. He's gotten back to me and is interested in
> > setting up some tests.
> >
> > What additional hardware, other than the transceiver and antenna,
> > should I have to try this? I've been tinkering with Arduinos, Cory had
> > mentioned earlier, but I'm not sure where they fit in.
> >
> > If there is anything that I need to buy out of the US I'd like to
> > get it ordered and on it's way to Joel at RF Connection to have it
> > included in the package he's sending me.
> >
> > Thanks for your help!
> >
> > Ron VE8RT (30M WSPR as VE8TEA)
> >
> > On Thu, 12 Oct 2017 16:45:45 -0400
> > Cory Vickruck <crvickru at lakeheadu.ca> wrote:
> >
> > > Also I would be happy to setup an igate for him to test. I think I might be
> > > just out of range however. I am in thunder bay Ontario
> > >
> > >
> > > On Oct 12, 2017 4:31 PM, "Cory Vickruck" <crvickru at lakeheadu.ca> wrote:
> > >
> > > > After reading a bit more about the topic I am interested in trying it out.
> > > > How much power would be enough for reliable packets at 6m APRS?
> > > >
> > > >
> > > > On Oct 12, 2017 2:36 PM, "Cory Vickruck" <crvickru at lakeheadu.ca> wrote:
> > > >
> > > >> Could PSK-31 be a option? Maybe fsq would be a good option as it can be
> > > >> interfaced with an Arduino.
> > > >>
> > > >> On Oct 12, 2017 2:12 PM, "Robert Bruninga" <bruninga at usna.edu> wrote:
> > > >>
> > > >> We have had great success with APRS Meteor Scatter on 6 meters, but I have
> > > >> not done it since 1996? Maybe its time for some new blood. Let me see if
> > > >> I can find the results of our first National APRS Meteroscatter test.
> > > >>
> > > >> Everyone, meet Ron, VE8RT who needs to communicate probably by APRS using
> > > >> Meteorscatter from the great Northwest... He currently is not on the
> > > >> APRSSIG and so reply here so we can see the interest, and I will forward
> > > >> any useful replies to him. Bob, WB4aPR
> > > >>
> > > >> -----Original Message-----
> > > >> From: Ron VE8RT [ve8rt at yknwt.ca]
> > > >> Subject: 6M APRS via meteor scatter forum?
> > > >>
> > > >> Hi Bob,
> > > >>
> > > >> I'm looking for a forum, if there is one, on meteor scatter and APRS.
> > > >> I'm one of less than a score of active amateur radio operators here in the
> > > >> Northwest Territories of Canada. The majority of amateur radio activity
> > > >> is here in Yellowknife (the capital), with distances of over a thousand
> > > >> kilometres seperating some of us. HF propagation is generally poor and
> > > >> unreliable, so I'm looking into 6M meteor scatter APRS or other digital
> > > >> modes for emergency communications.
> > > >>
> > > >> I had joined the TAPR APRS SIG forum for a few days, having posted my
> > > >> introduction and my interest in meteor scatter APRS, but it didn't
> > > >> generate any replies (so I unsubscribed).
> > > >>
> > > >> Would you have any suggestions?
> > > >>
> > > >> Thanks,
> > > >>
> > > >> Ron VE8RT in DP22
> > > >> --
> > > >> Ron VE8RT <ve8rt at yknwt.ca>
> > > >> _______________________________________________
> > > >> aprssig mailing list
> > > >> aprssig at tapr.org
> > > >> http://www.tapr.org/mailman/listinfo/aprssig
> > > >>
> > > >>
> > > >>
> >
> >
> > --
> > Ron VE8RT <ve8rt at yknwt.ca>
> > _______________________________________________
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> > aprssig at tapr.org
> > http://www.tapr.org/mailman/listinfo/aprssig
> >
>
>
> --
> Ron VE8RT <ve8rt at yknwt.ca>
> _______________________________________________
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>
--
Ron VE8RT <ve8rt at yknwt.ca>
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