Monday, 10 March 2014 13:56

APRS services

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Fun things to do with APRS

Email, Text Message, Callsign lookups, are only a few other things that you can do with APRS.

GPS tracking is a well known use for APRS, but there are many other things you can do with your radio and using the APRS network.  I've just started experimenting with APRS with my Kenwood TH-D72a HT dual band radio and wanted to document a few things I've been playing with.

  • Email
  • SMS
  • APRS to Twitter
  • Callsign Lookup
  • SatSRV
  • + More

Once your radio is tuned to the APRS network (144.390 here in the US), and connected up to a TNC (hardware or software), you can start having some fun on the APRS network.  You can message to and from other radio on the APRS network, send/receive email, do a callsign lookup, or even send the message through the ISS or other satellites.  I will try to document a few of the things here that you can do besides sending out your GPS coordinates and do my best to be sure the information is accurate.



There's different ways to send and receive email using APRS.  Here's just one example.


Send a simple 1 line email

[Message To] [Message Body] - Max 67 Characters
  Recipient's email address [space] message
EMAIL This email address is being protected from spambots. You need JavaScript enabled to view it. Hi John, This is an email from my HT.

For more in-depth look at sending and receiving emails, check out my page APRS Email Info Page where I discuss several different ways to send out your emails and I also provide details on how to send an email back to a radio on the APRS network.


SMS (Text message to a cell phone)

Send a SMS (Text Message) to a cell phone with APRS from your radio.  This works by using the cell phone providers "email to sms" gateways.  Unfortunately you need to know the carrier of the person you are trying to message and there is no easy way for them to reply easily to the txt message.

Here are some of the more popular US carrier addresses.  For other carrier's not listed here, try

Cellular One:
US Cellular:
Virgin Mobile:


[Message To] [Message Body] - Max 67 Characters
  Recipient's 10 digit cell phone# + their carrier's address [space] message
EMAIL This email address is being protected from spambots. You need JavaScript enabled to view it. Hi this is a test from my radio to your phone!

20140521 - I confirmed that this worked with my carrier (at&t).  The message on the phone is a little sloppy as it not only sends "your" message but all of the text you normally see in the EMAIL server's emails.
20140521 - I confirmed that this worked using EMAIL-2 server as well, same sloppy output to sms but it worked and setting up a shortcut with EMAIL-2 is nice to save from typing from the radio's keypad.


APRS to Twitter

There seem to be a handful of ways to send out tweets using APRS.  The first one I came across was using website, since then a few people wrote some scripts to allow you to do this as well.  I currently do not have a twitter account, but I guess I'll be setting one up soon to test this out...and to be a little more current with the times...


You have to create an account on (free) and then setup in your profile settings to link with your twitter account.  Now doesn't have direct access to your password in doing this, but will have access to sending tweets (or else it wouldn't work!).  I will update more once I setup an account on twitter :)


The website also allows you to quickly setup a way to link your callsign to your twitter account.  I haven't tried it myself but seems very easy.  You can find out about how it actually works here  Once you have linked your account on his website with your callsign you can then tweet:

[Message To] [Message Body] - Max 67 Characters
  tweet: + [message]
YO3IIU-11 tweet: Hello World!


  • aprs2twitter

There is also a script that you can download written by KD8BXP that allows you to host your own gateway.  It is written in php and requires some setup which means it allows you to customize it to your liking.  I will likely be setting this up in the near future and see where it goes.  You can read about the script details here


Callsign Lookup

Lookup callsigns with APRS

  • WHO-IS
[Message To] [Message Body] - Max 67 Characters

Send a message to WHO-IS with the callsign as the message, it will send you back (over APRS) in a one line message format the basic details of the callsign owner (CallSign/License/Name/Location)

[Message To] [Message Body] - Max 67 Characters
  f [space] Callsign

Send a message to WHO-IS with the letter f space and the callsign as the message, it will send you back (over APRS) in a multi-line message format the full details of the callsign owner.


  • DOQRZ (Currently DOWN as of 20140310)
  • SAQRZ (Currently DOWN as of 20140310)


ANSRVR - need to update

This is from my understanding the updated CQServer.  Join discussion groups similar to email lists on a wide variety of subjects.  I haven't had much luck with this, although I can subscribe to the groups, there hasn't been any activity when I do.  [need to add more details...]



Recently since I have started playing with APRS, I thought to myself, why isn't there a way to get upcoming satellite passes over APRS.  How great would that be, I even started thinking about writing some code to interact with Predict, a command line satellite tracking program.  Well apparently there already is something in place to do this, SatSRV.  You send a message directly to the satellite name (no dashes) and you will get a message back with the current or the upcoming pass for your location.

[Message To] [Message Body] - Max 67 Characters
Satellite Name [no Dashes] [anything - my radio won't send an empty message]
NO44 1


You will receive a message back like:

Pass Time
Response Format
Sample Response
 More than an hour away AOS time (dd hhmmz) dir^mx AOS 1h13m (1936z) N^76
Less than an hour away AOS time dir dir^mx dir +duration AOS 49m57s W NW^76 E +11m
Ascending in a pass dir^el dir^mx dir LOS remaining W^15 N^76 E LOS 7m48s
Descending in a pass dir^el dir LOS remaining NNE^75 E LOS 5m11s
No passes for your QTH No AOS Within 2 Days No AOS Within 2 Days


AOS Acquisition of Signal
LOS Loss of Signal
time time in hours/minute or minutes/seconds until AOS
dd hhmmz zulu time of AOS (dd is suppressed if today)
dir compass point (8 points pre-pass, 16 points within pass)
^mx maximum elevation expected
^el current elevation during a pass (always first)
duration expected duration of the pass (in minutes)
remaining time remaining (minutes/seconds) of the pass



Only satellites in this list will work

If your position is not known, it will send a message back asking you to first beacon your position to the APRS network "Please Beacon Position"

Thanks to for most of this information.


Check APRS status via email

(Currently DOWN as of 20140521)

I found this website, but it doesn't appear to be working, I tried it using yahoo (plain text format as required) and my callsign (lowercase/all caps/with SSID/without SSID) and it always returned callsign not found.  The idea is to send an email to This email address is being protected from spambots. You need JavaScript enabled to view it. with the person's call sign, and it will email you back that person's APRS status (last heard, position, status).


Send APRS messages from the Web

  • Method 1 (not confirmed)

I haven't testing this yet but over at you can send messages directly to the APRS network from the web.  An APRS password is required.  It looks interesting because it allows you to also send RAW packets for troubleshooting and testing.

  • Method 2 (confirmed?)

You can use findu's web portal to send a message directly to an APRS user.  I tried it out and although I do see the sent message on the APRS network when I search for my call sign on, but I do not receive it on my radio.  It may have something to do with the iGates nearby and/or my weak signal, I need to experiment with this some more.

  •  Method 3 (confirmed?)

You can signup for a free account over at, once you verify your account (either by radio - sending a APRS message to the owner with a key, or via paypal - a small donation) you can send messages to other APRS users with their web portal.  Just like the findu service, I was able to see the message online viewing raw APRS packets, but I did not receive it on my radio.  It may have to do with the iGate I am near or my signal.  One nice thing about this service is that ihe message gets sent out multiple times for better reliability.


Interact with the APRS network via DTMF tones

APRStt  I need to do some more research and experimenting with this.  I am not clear on how to locate APRStt gateways or even if there are any permanent ones out there.  It appears to be able to be linked in with standard voice repeaters as well as the use of stand alone gateways.  This seams like it can be interesting to play with, and possibly linking it to my VoIP freeswitch server somehow.  Hopefully I will be able to find time soon to play with this some more.


Send APRS messages via satellites

This is what first got me interested in APRS, the fact that I can send messages with my HT and a telescopic whip antenna through space.  I am currently doing a few experiments right now on which satellites are working (ISS, NO-44 provide digipeater paths to the APRS network (ASTARS) and are currently operational) and to see if there are other satellites operating to allow for point to point contacts with APRS messaging.  If you have the local APRS network figured out (frequency, PATH, etc) you will have more to learn to work the satellites.  I am currently working on a page that describes further details and information on how to communicate through the satellites here

I am learning as I create the guide so hopefully it will help others out as well.  Here is the basic information to work ISS and NO-44 with APRS, for more detailed information go here

ISS (Zarya)
 Frequency (Simplex): 145.825 MHz
Mode: 1200bps AFSK


NO-44 (PCSat-1)
 Frequency (Simplex): 145.825 MHz
PATH: 1200bps AFSK




Read 15801 times Last modified on Thursday, 24 September 2015 15:15
Algis Salys

Creator and owner of  Linux enthusiast, electronics tinkerer, and likes to spend time in the workshop building and creating new projects.