So when I try to work the ISS digipeater, what should I set the digi path to be?

My setup is a 5 W HT with a 2 m yagi connected to my phone with APRSDroid.

I've tried the past few nights with ARISS R0ISS and WIDE2-2 and none seem to get picked up (granted some passes I've tried haven't been very high, ~25°).

EDIT: I can hear and decode MANY packets (more than I can generally hear while on 144.390 APRS in my area). I'm also adjusting for doppler shift. I've not heard of adjusting for polarization, what would that entail? I'm using a 3 beam yagi that I made and generally try and track it while holding it generally horizontally. I apologize, I'm fairly new to this; I've had my Tech for a few years but haven't done much with it until recently.

  • $\begingroup$ Need more info - like, for instance, can you hear the signal? What kind of antenna, whether you are adjusting for doppler and polarization, etc. Welcome to Amateur Radio SE - be sure to take the tour at ham.stackexchange.com/Tour to get the most out of this site. $\endgroup$ – SDsolar Jun 9 '17 at 0:32
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    $\begingroup$ @SDsolar No, the question does not need more info. The question as originally posed is “What digi path should I use” which is a good, objectively answerable question. Troubleshooting the contact attempt in general is more likely to go off in the weeds of “have you tried this?” $\endgroup$ – Kevin Reid AG6YO Jun 10 '17 at 1:39
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    $\begingroup$ @Jrw3 It looks like you've got two accounts by accident. Here's how to get that fixed. $\endgroup$ – Kevin Reid AG6YO Jun 10 '17 at 1:41
  • $\begingroup$ @KevinReidAG6YO Thanks I didn't realize. Should be fixed now. $\endgroup$ – JW03 Jun 12 '17 at 14:17
  • $\begingroup$ I am a little to the game with my suggestion but, have you considered joining the AMSAT organization? AMSAT bulletinboard amsat.org/pipermail/ans $\endgroup$ – SecurityDoctor Mar 21 '18 at 13:49

According to the PDF that Duston mentioned, your UNPROTO path should be CQ VIA ARISS. WIDE2-2 would cause your packets to be repeated twice if terrestrial digipeaters should hear them. Presumably you're using the ISS VHF APRS frequency 145.825 MHz rather than the North American terrestrial APRS frequency 144.39 MHz, so WIDE2-2 packets shouldn't be unnecessarily digipeated, but WIDE2-2 would be incorrect.


According to this PDF, if you want to send APRS data via the ISS, you format your UNPROTO packet with the data you want to send. The digipath is irrelevant because you're going directly to ISS.

I used a plain old vertical antenna with not a lot of power and got packets through.

  • $\begingroup$ I was under the impression that UNPROTO was a normal TNC mode/packet thing, not having to do with APRS. Should I set my digipath to WIDE2-2 then? Sorry I'm still new to APRS $\endgroup$ – JW03 Jun 16 '17 at 18:40

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