Questions tagged [aprs]

Automatic Packet Reporting System is a digital protocol used to transmit GPS position reports, telemetry, weather reports and text messages between APRS compatible devices and software.

The APRS system consists of the following components:

  • Trackers, small microcontroller-based devices which, when connected to a GPS receiver and a transmitter, transmit their location regularly over radio. Some trackers feature integrated GPS and radio modules. Trackers are available as kits, ready-made, and they're also relatively easy to build from parts.
  • Radio transceivers implementing the APRS protocol, such as Kenwood and Yaesu commercial offerings, which can act as trackers and normal voice radios at the same time, and implement text messaging and other APRS features
  • APRS applications for computers and mobile devices, typically having a tactical real-time map view of APRS stations
  • APRS web database sites, which provide real-time map views and historical APRS data lookup functions
  • APRS-IS, the APRS Internet System is a network of servers connecting radio-based APRS networks together over the Internet
  • The protocol itself, defining how the pieces of the system communicate

Questions concerning the APRS system or any of its components should have the aprs tag.

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Is there a disadvantage to using a cheap HT for APRS?

Looking to build a cheap (not even inexpensive, just dirt cheap) APRS beacon transmitter. Right now you can get a dual band handheld transceiver with rechargeable battery, antenna, etc for under $31 [USD], for instance. I can't find a cheaper…
Adam Davis
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How to do APRS in real wilderness?

I'm a relatively new ham (licensed a couple of years ago, occasional activity on 70cm and 2m, mostly repeaters). I'm looking to extend my ham experience and am interested in digital and packet modes. I'm interested in APRS. The main reason is to…
hamster
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How do I discover APRS coverage?

I'm considering adding simple APRS transmitters to my vehicles. I'd rather just put one in and forget about it, but I understand there are areas of the US where a stronger transmitter would be required to successfully send an APRS update…
Adam Davis
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When is APRS use considered commercial?

I've heard that APRS is only allowed for non-commercial use. I was thinking of a building a weather station that uploads data via APRS (so far, non-commercial). If I then include data from that weather station on a website with advertisements, is it…
Anssssss
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APRS digi path for ISS digipeater?

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…
JW03
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What Part 97 rule allows unattended, automated transmissions, such as APRS weather stations and beacons?

What rule allows Amateur Operators to establish and operate remote, automated stations like APRS weather stations or beacons? Are there different rules specifically for beacons, or do they all fall under the same rules?
Adam Davis
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Is it possible to overload APRS?

Does APRS have a limited capacity in terms of beacons? What happens when an APRS frequency experiences a large number of packets?
JC Hulce
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Help understanding path taken by APRS packet

I'm looking at some raw APRS packets over APRS-IS. I'd like to determine which stations heard particular packets, but I'm having trouble understanding how TNC-2 paths work. Here are two examples: 2016-05-19 05:51:46 PDT:…
watkipet
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Is there a difference between AFSK and FSK for AX.25/APRS USE?

APRS uses the AX.25 protocol which assumes the Bell 202 AFSK modulation scheme to generate the actual radio signal. Is there any reason the same signal can't be generated directly with FSK without going through the audio frequencies? My reading…
jgalak
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Do aprs.fi and APRS-IS use the same credentials?

I have an account/profile on aprs.fi, and now I am trying to use APRSdroid, which requested my credentials. Can I use the password from aprs.fi for it? I am unable to register/submit my application through TQSL because my country is not on the list.…
harayz
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What should be the modulation when transmitting APRS signal?

Is it SSB or NFM or other type of modulation?
Harold Chan
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APRS: WIDEn-N vs. TRACEn-N

The suggested APRS digipeater path is WIDE1-1,WIDE2-1 for the most use cases. According to the specs, this ensures two retransmissions by fill-in / regular digipeaters around the sender, without the digipeaters adding their own callsign to the…
Georg DO1GL
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Can I still use my Kenwood TM-281A for normal communications even while I have a TinyTrak4 connected for APRS use?

I am considering buying a Byonics TinyTraK4 to connect to my Kenwood TM-281a to do APRS. However, I am wondering if I should instead buy a separate radio (I am considering a Baofeng UV-5R) as well and connect the TT4 to it instead of the TM-281A. My…
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What's the difference between an APRS "item" and an APRS "object"?

What's the difference between an APRS "item" and an APRS "object"? A kenwood manual says Objects have timestamps, items do not. What does that mean, and how should it be used? Also in general: What is a good resource for learning about APRS?…
Thomas
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AX.25 on macOS (aside from APRS)

I'd like to send raw AX.25 packets from a macOS PC using a KISS TNC (mobilinkd TNC2). I've sent APRS packets with this set up using Xastir, but I'd like to send other information besides just APRS (i.e. put my own information into the AX.25…
watkipet
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