APRS Config with Keps

[UT7UX]

As far as I know, standard satellite APRS alias 'ARISS' for some reason doesn't work with ISS anymore; we temporally have to use RS0ISS instead. So, I believe the correct path fort ISS would be 'RS0ISS,APRS' since we'd like our beacons to be bounced from onboard digi and to get to APRS-IS via a satgate. Sure it could change anytime or have already changed. Also, WideN-n is too way redundant since ISS provides enormous coverage so needs no terrestrial relaying. Please correct me if I'm wrong.

Another point is that since OpenGD77 only transmits beacons, it is a tracker but neither primary nor mobile/portable station. According to the convention, trackers should use SSID-12 whenever is possible as well as avoid SSID-7 and SSID-9. Also, position ambiguity cannot be set for SAT beaconing. Is it possible to make appropriate change in APRS Config by the user?

IMO it would be great if SAT APRS will rely on one of presets we use in normal (not SAT) mode beaconing or have user-friendly settings somewhere in the CPS apart from normal mode beaconing.

[DW7GDL]

As far as I know, standard satellite APRS alias 'ARISS' for some reason doesn't work with ISS anymore; we temporally have to use RS0ISS instead.

How do you know this? Do you have a source or reference for this information? I ask because I've lately been trying to hit the ISS's digipeater and send a position report with my RT3S with no success so far, but only 2 attempts, and there's an 87 degrees pass in 5 days which will be as close to being directly overhead as it gets this month.

In any case the file satellites.txt (which Windows' File Explorer insists on displaying as merely "satellites") exists in the OpenGD77CPS directory in C: > Program Files (i386) and can be edited and saved then the codeplug uploaded to the radio. I would first download the latest keps first before you edit the file and save it, not long before you want to send an APRS position report.

[SA0BUX]

I looked on aprs.fi and ARISS has not been seen since "2024-04-13 18:12:51 CEST (51d 20m ago)"

RS0ISS has been active:

Code: Select all

2024-05-31 15:54:58 CEST: RS0ISS>0P0PS3,APRSAT,qAO,EA8DEJ-1:'v&<0x1c>l <0x1c>SI]ARISS-International Space Station=
2024-05-31 15:57:58 CEST: RS0ISS>0P0PS3,APRSAT,qAO,EA4BPN-10:'v&<0x1c>l <0x1c>SI]ARISS-International Space Station=
2024-05-31 16:00:58 CEST: RS0ISS>0P0PS3,APRSAT,qAO,LY1RF:'v&<0x1c>l <0x1c>SI]ARISS-International Space Station=
2024-05-31 16:03:58 CEST: RS0ISS>0P0PS4,APRSAT,qAU,OK2KZO-2:'v&<0x1c>l <0x1c>SI]ARISS-International Space Station=

[DW7GDL]

Thank you. I managed to edit my satellites.txt file and save it then uploaded my codeplug to the radio. I hope the modified satellite.txt info is included in that upload but I won't be able to tell until the next near pass of the ISS and hear if it's digipeating my packets now.

From what I can tell the APRS path isn't included in the source keps data so it may be something added by the CPS in the process of converting Celestrak's amateur.txt file to satellites.txt for OpenGD77? Anyway, I'm not sure who needs to correct it to make ISS's APRS work again.

[UT7UX]

How do you know this? Do you have a source or reference for this information?

Fellow ham told me that so I cannot provide a link or other clear proof. So, I changed ARISS with RS0ISS and got my packets bounced off ISS digi. Same time my recent attempts to beacon with my new OpenGD77 HT were unsuccessful.

I ask because I've lately been trying to hit the ISS's digipeater and send a position report with my RT3S with no success so far, but only 2 attempts, and there's an 87 degrees pass in 5 days which will be as close to being directly overhead as it gets this month.

ISS is pretty deaf so a kind of better (read: longer) antenna is pretty welcome still during near overhead pass whatever gear is likely enough to be confidently heard by ISS. Some your beacons may be unintentionally jammed by other stations so for testing repeat beaconing until you see your beacons arrive on Findu or whatever APRS-IS aggregation site.
Did you hear any packets from other stations I mean are you sure the digi was operational that times? During some passes onboard TM-D710 is either switched to X-Band FM voice repeater or completely turned off.

In any case the file satellites.txt (which Windows' File Explorer insists on displaying as merely "satellites") exists in the OpenGD77CPS directory in C: > Program Files (i386) and can be edited and saved then the codeplug uploaded to the radio. I would first download the latest keps first before you edit the file and save it, not long before you want to send an APRS position report.

Yeah, found that with your help, thank you very much. That's exactly what I wanted to play with.

[UT7UX]

I looked on aprs.fi and ARISS has not been seen since "2024-04-13 18:12:51 CEST (51d 20m ago)"

I would rather rely on this source. You can switch between age and absolute date & time to see how far ago last station was heard. Any time I do successful beaconing or exchange messages with other stations I see myself among last heard calls.

I managed to edit my satellites.txt file and save it then uploaded my codeplug to the radio. I hope the modified satellite.txt info is included in that upload but I won't be able to tell until the next near pass of the ISS and hear if it's digipeating my packets now.

Have you got whatever else radio like FM HT or maybe an SDR receiver to monitor your packets? I personally use an HT (the cheapest Chinese one would work just fine), audio cable, and APRS droid software; this also works for TX but has limitations due too long VOX tail with some radios. Still, it's quite possible just to place a phone near TH with the phone's mic facing towards the radio loudspeaker.

[DW7GDL]

I heard one packet the other evening when I tried, before I had edited satellites.txt. I know my packets are getting out because I can hear them on other radios. I'm going to keep trying, this time connecting the RT3S to a roll-up dual band slim jim (basically a folded dipole) that's hanging up around 8.5 meters high and should be more clear of local obstructions (houses), then I can try from the comfort of my own shack without having to go out onto the street somewhere. (I have a Comet SO-239 to SMA male adapter cable around 50cm long made with RG-186.) Someday there will be a combination of a close pass and the ISS APRS/packet radio being turned on and working.

[DW7GDL]

I tried again just now during an 87 degree pass. I was digipeated 8 or so times but I'm not showing up on either ariss.net or aprs.fi. Apparently their aren't any 145.825MHz igates in my part of SE Asia. Oh well. At least I was able to hit the ISS's service module packet radio. I guess that's something, anyway. Some 4450 km. on 5 watts.

[UT7UX]

I was digipeated 8 or so times

So, it does work. Great!

[YO3ABC]

Hello

I m trying to hit the ISS's digipeater with my DM-1701
and send a position report unsuccessfully.
Can you post your satellite.txt ISS settings?

Thank you very much
YO3ABC