Amateur Radio
Universal Text Messaging/Contact Initiative

Bob Bruninga, WB4APR

Initiated Jan/Feb 2009, Pending approval of the Amateur Radio Advanced Project Development Committee

Identified below are more than TWO DOZEN Amateur Radio TEXT MESSAGING systems. The purpose of this web page is an initiative to tie them all together! A parallel initiative (called AVRS) is to tie together all the Ham Radio VOIP systems as well so that we have universal callsign-to-callsign connectivity, both Texting and Voice!

Sept 18 Universal Connectivity-by-callsign Sunday Workshop at the ARRL/TAPR Digital Communications Conference! Please come join this workshop and help us figure out how to tie this all together!

Universal Local and Global Text-Messaging -by-callsign- is needed throughout Amateur Radio. Although text messaging has been a fundamental APRS capability for over 17 years and is now embedded in many APRS amateur radios as shown here to the right, I count over 26 other Amateur Radio Text-messaging capabilities below that are not yet fully integrated into a single over-arching amateur radio-wide capability! Yet it would be so easy to do... if we just got excited about the possibility and did it!

After 9/11 and Katrina it was clear that amateur radio needs immediate responsive communications to simply locate and establish initial communications. Such fundamental local/global communications are trivial on the National APRS frequency. . This web page summarizes all of the capabilities for TEXT-Messaging not only in dedicated APRS radios shown to the right, but ALL radios and ALL devices in the field including cell phones!

Surely, every Ham radio operator can find one of these techniques below he/she can use!
And if we tie them all together, then it doesn't matter what he uses! ANY Ham, ANY where, using ANY device can text message ANY other ham, ANY where, on any of his devices, knowing nothing but his CALLSIGN!

The remainder of this web page discusses the existing systems that involve amateur radio text messaging in the following Broad Categories:

  • Organic Packet Systems: all existing APRS and Winlink systems can send and receive messages
  • Text Paging Radios: 500,000 DTMF text paging amateur radio HT's were sold in the 90's
  • All other HT's with DTMF: Every radio with a key pad can send brief text messages
  • DTMF decoding software: can receive and display these messages
  • Other Consumer Devices: Applications on cellphones and other hand-held devices to TX/RX APRS messages
  • Ham Radio Voice Internet systems: Echolink and IRLP can exchange text messages
  • APRS Internet Systems: can send and receive text messages and email such as the following:
  • APRS -to- Email: Sending an email from any APRS or compatible system [exists]
  • WEB page -to- APRS: Amateurs using Browsers to send into the APRS system [exists]
  • SMS -to- APRS: Global text messaging to APRS users
  • EMAIL -to- APRS: Global Email to APRS users


    APRS RADIOS: . For APRS client software and APRS built-in radios (shown at the top of this page) it is trivial to send and receive text-messages and Email on their front panel. The TH-D7 display is shown above... In this case, it is sending an Email. . Just press the MSG button, select INPUT on the MSG Menu, enter EMAIL as the address, and make the first text of the message be an email address followed by your message. . In the example above, an EMAIL to A3XYZ@AMSAT.ORG says OK in OceanCity with HT & whip!. . If your email is digipeated, then you will see MY MESSAGE flashed on the screen indicating success.

    UI-Instant Messenger was written by Andy Pritchard to correct the problems with some details of APRS messaging that were not complete in UIview. His add-on not only improved UIview's efficiency in handling messages, but the program can also operate stand-alone as an application with the AGW Packet Engine, or as a direct IP client on Internet connections. Use it as a replacement for the messaging function inside UIview to overcome the lack of the proper decaying repetition rate for unacked msgs and the lack of the full ACK algorithms of APRS.

    Winlink Text-Messaging: . An APRS interface has been added to the Winlink system so that any APRS radio can be used to send and receive Email via the Winlink system. The system is called APRSlink and was designed by Lee, K0QED. It allows any APRS radio operator to log in and send/receive email via Winlink using only the front panel display and keybad of the radio. In addition to full two-way Winlink and Email messaging, there are two other features that fully link Winlink and APRS for quick messaging:

  • One-Line Messages: One line messages can be sent from any APRS radio or HT to any winlink address (callsign, or email) by sending the message to WLNK-1 and having the first two words of the message be SMS ADDRESS where SMS alerts the WLNK-1 server to convert the one line to a standard SMS message and the second word ADDRESS is either a winlink callsign or an email address.
  • Message Alerts: You can receive message alerts on the front panel of your APRS radio each time your Winlink account receives a new message. This is automatically activated as long as you have the callsign WLNK-1 in your position somment or status text. Something like QRU WLNK-1 would to the trick nicely.

    MultiPSK by F6CTE has a built-in APRS packet message mode.


    Message Displays on Any Radios: . There are many devices that can turn any two-way radio into a Universal Text-Messaging device by simply adding an APRS display system at the speaker/mic interface.

  • HAMHUD: Shown here to the right is the HAMHUD that gives a display and basic text entry capablity to any radio by connection to the speaker-mic connection. It includes the TNC and all needed input/output capability. Previous models used an external TNC, recent models include the TNC, and future models have many many new features.

  • TINY-TRACK-4: The new Tiny-Track-4 is a full 2-way but low-cost APRS device that not only serves as a mobile APRS tracker and display system, but also it can be configured as a stand-alone digipeater. It includes an optional Text display for mobile info, objects and text messaging.

  • Tracker2 Messaging with Nuvi 350: Argent Data Systems has added a capability to his OT2 trackers that alow users of the older NUVI 350 GPS units with front panel "fleet messaging" capability to send and receive APRS text messages through the use of the Garmin serial cable. These GPS's with the tracker2 interface also do some symbol translation from APRS symbols into the Garmin symbol set. Although this model of NUVI is no longer available, the combination makes a great innexpensive APRS mobile system if you can find one.

  • RC-D710: The full-up, but more expensive option, of course, is to simply add the RC-D710 APRS Display Head to any radio. This Display head, that comes with the TM-D710 APRS radio, can also be purchased separately so that it can be added to ANY radio at the speaker-mic level. The full APRS functionality of this fully integrated APRS system is all contained in the display head including the TNC, so it is transportable to any radio. Take it indoors with your HT and use it at your desk attached via audio cable to your HT. Shown here, it is attached to an $88 Alinco HT (with 9 AA NiCd's to power it's 350 mA needs).

    Message Displays on Paging Radios: . In addition to the APRS radios, there are an estimated 500,000 FT-51R family and TH-78A radios (from the 1990's) that have a built-in TEXT messaging and paging function that can also be used for messaging. Messages are entered from the Keypad and displayed on the radio front panel. Messages can also be received and displayed on PC's using simple DTMF decoding software. But not only can this capability be used for sending and receiving text messages, we can also push other important local information to the front panel displays of these radios. . For example, the locally recommended voice frequency for travelers and visitors. Please see details on how we can integrate this into APRS.

    Surplus Text Pagers: With the rise of the cell phone industry there appear to be thousands of low cost text messaging pagers that can be easily converted to amateur frequencies. These would allow anyone with one of these pagers to receive APRS messages, and local APRS bulletins, and information from a local APRS->POCSAG gateway. This would be integrated with APRStt so that the same user could show where he is and enter his callsign by DTMF on his existing HT or mobile. There was some work on ham radio paging networks in Germany by DL3SDW back in 2003 It would be easy to tie these pagers into the Universal Text Messaging System with something as simple as a Xtal change and a little firmware in an APRS-> POCSAG Gateway. A POCSAG encoder is built into every Kantronics KPC-9612 TNC.

    DCS-Text Messaging Radios: . Still newer radios use the DCS codes to send and receive text messaging. Again, gateway software can be written for these radios as well so that they can send and receive ham radio text messages with not only themselves but any other ham radio, APRS radio, DTMF radio, Cell phone, Blackberry or what have you. Known radios with the DCS-Text Messsage capabliity are the VX-8R, VX-3R, and FTM-10R/SR. See Message set-up, Member list, and Sending & Receiving

    All Other Radios with DTMF: . There are two methods for Text Messaging using the simple DTMF built into almost all amateur radios. First is sending in the paging-format defined above for the older Text Paging radios. These messages can be sent by ANY radio, and received on the special paging radios above or on a separate DTMF decoding software on a PC. See an example here. . Secondly is the APRS Touchtone project started in 2001 using the gateway program calld APRStt. This DTMF Messaging extends basic information exchange to all radio amateurs, not just those that are APRS equipped. . Even the old crumudgen that shows up with his venerable IC-2AT for example can participate. . Reading your text messages is as simple as entering your callsign in a DTMF memory. When you send your pre-loaded DTMF callsign on the APRStt voice frequency, the APRStt engine will respond by voice with any listed traffic and will read them to you on demand. . See the APRStt web page.

    D-STAR Radios: Although the Dstar radios do not have any built-in radio-to-radio text messaging capability, they can be connected to PC's on each end and with the right software such as (D-rats), users can then keyboard message similar to other systems.

    Automatic Link Establishment (ALE) Radios: Not only do ALE systems on HF provide for call-up-by-callsign voice connectivity, but they also provide a minimum TEXTING capability. There is no reason why a text sent on ALE is not also delivered to the same callsign's APRS radio and Vice Versa. See the Global HF ALE web page.

    MESSAGING ON OTHER DEVICES: . The goal here is to encourage the development of applications for all typical wireless devices that will enable them to exchange text-messages with any other ham radio operator by callsign addressing. This can tie in all user wireless devices into the global APRS system to greatly enhance communication in support of emergency and event communications. These applications can be simple for messaging only, or can bring in full APRS map displays as well. See how simple it is.

    OLPC APRS INTERFACE: . Every laptop and palmtop held by ham radio operators needs a text-messaging interface to ham radio. For example, this interface for the OLPC (One-Laptop-Per-Child) laptop named the XO checks into the APRS system and can send and receive APRS text-messages and email whenever the OLPC is in WI-FI range. This activity was written by Jack Zielke, KG4GJY. See the web page for installation and operation. Again this November, the OLPC is being offered under the buy-one-give-one-free program at

    APRS Messages to Your Cellphone: . N3FLR Frank Rossi reports that he uses "YahooAlert" to send all of his APRS messages to his cell phone. First, Find-U has RSS output capability so he has his computer RSS Feed Reader watching his Feed From FindU, and YahooAlert also watching. After setting up Yahoo Alert for a pager, he uses his phone's text e-mail address such as . Then you just need to know what your phone's "e-mail address" to "text address" is. You don't need mobile internet to do it this way, just text ability. That will work with a text pager also. . When FINDU sees a message to him on APRS it generates an RSS Feed that now Yahoo-Alerts is watching. YahooAlerts then forwards the RSS Message as Text to his cell phone. Although this is only one way communications, it still lets him receive his APRS messages. He also says that you can set up RSS feeds from FindU for weather alerts, or APRS users X amount of miles from you. You can make the miles anything you want. He has not tried that function yet.

    APRS Messages to/from Your IPHONE:. NV6G, Greg announced his beta iPhone application and AB3Y, David Ponevac, has developed another application called IBCNU that not only provides APRS messaging, but position reporting as well.

    APRS on Windows-Mobile 5&6: . Lynn, KJ4ERJ, author of APRSISCE mentions that he has an APRS-IS client (beta) running for Windows Mobile 5 and 6 specifically tested on the AT&T Tilt and maybe the SmartPhone (Motorolo Q, I believe)... See his mobile KJ4ERJ-12 on FINDU.COM or APRS.FI. This can bring APRS to every ham with these cell phone devices!


    Any APRS station can send brief text-messages using email via APRS to any cell phone or Internet user. The technique is extremely simple. Just address your APRS message to one of the Email engines below and make the first word of the message be the intended email address followed by the message. This is automatically picked off the APRS-Internet-System (APRS-IS) by the email engine and sent via conventional email. The sender receives an APRS ack for the message.

  • WU2Z Email Engine: . . .The original APRS Email system. Send to "EMAIL"
  • AE5PL Email Engine: . . Send to "EMAIL-2". . See additional info.
  • VK3JFK Email Engine: .Send to "SAMAIL". . See details.
  • APRSlink on WLNK-1:. Send to "WLNK-1" using the "SP" command (See how)


    There are a few methods for sending APRS messages from on-line APRS-Internet (APRS-IS) systems to APRS mobiles and handheld operators. . We hope that such systems implement the full APRS message mechanism to assure reliability and accountabliliy (see issues). Here are some systems:

  • K4HG, Steve reports that FINDU.COM now has web based messaging. . For example, this entermsg.cgi link will allow you to send a message from your browser to any APRS user.

  • NV6G, Greg reports that has full messaging support since August 08. . Just signup for an account (which is free), messaging is under the Tools window which is accessed from the right icon bar. OpenAPRS includes a "Friends List" that will display when OpenAPRS has detected one of your friends sending APRS messages to let you know when they are online.


    There are a number of Amateur Radio software applications that tie directly to the internet giving the operator direct text messaging and email capability to all other users of that same internet application. For example APRS users on the internet can fully text message each other, and Echolink users can also fully text message each other, yet it is silly that they cannot talk to each other!

    APRS CLIENT PROGRAMS AND IGATES: . Almost all APRS client programs include an internet interface so that not only can the operator see the local RF tactical situation, but he can also see the global network as well. As such he can text message anywhere in the world to both RF and internet users alike. In fact, it is these home client stations that also provide all of the internet-gateways (IGates) that provide the global connectivity that makes APRS so universal.

    ECHOLINK and IRLP: These two very powerful Voice-over-IP systems provide the same kind of global connectivity to amateur radio voice operations as APRS provides to digital operations. Echolink has operator-to-operator text messaging, and this system needs to send parallel copies of those messages to the same callsigns in APRS, so that if the Echolink operator is not at his operating position, but might be mobile, then the same message can be delivered to the front panel of his APRS radio in real time!


    Getting standard SMS Text Messaging and standard SMTP Email to the end APRS User in the field via his radio is the one remaining un-fulfilled link in the Universal Ham Radio Text Messaging System. Our goal is to be able to send and receive text messages no matter what the device and no matter where they are. This includes sending from cell phones, palm-tops, blackberry's, pagers, and any other portable device. The fundamental obstruction to this simple yet powerful capability is simply the need for security and filters to protect the RF links from overload, possible abuse, and inappropriate material and spam.

    SMS TO APRS SYSTEM IN NORWAY: . Kai Gunter, LA3QMA reports a system allowing Norwegian HAMS sending SMS to an APRS station. . For this to work they first have to send a SMS to a short numer 2440 with APRS as the "codeword" and the APRS-IS passcode and callsign. . If the passcode is correct for the callsign this mobilenumber is stored so that the user can send a SMS to an APRS station without this procedure the next time. . Additional goals for the system are to send the static picture as an MMS. The APRS ==> SMS direction is not yet implemented. One issue is "roaming" due to accounting and costing issues.


    There are (and have been) many Amateur Satellites that are enabled for text messaging. Since most of these satellites are accessible just about from anywhere on earth a few times a day, they make excellent ways to get a message out of a wilderness area. Existing working satellites are PCSAT-1, ARISS and the many older satellites mentioned in ASTARS. . In an effort to encourage text messaging via those satellites, we encourage a satellite version of the Simulated Emergency Test called SSET. . The objective of SSET is to see how many amateur operators can get an APRS email text-message sent via satellite using only their APRS HT or mobile rig.

    APRS-INTERNET and I-GATE IMPROVEMENTS: A major initiative to support all of this Universal Text Messaging concept is to improve the end-to-end reliability of the message delivery from the APRS-Internet (APRS-IS) system back to RF and the end user's radio. A first step in that direction is an upgrade to all IGates to have them report-back to the APRS-IS the status of their delivery of the message. Did they deliver it to RF? Using what rule? How many hops? See the details of the Igate-path-report project.

    OTHER APRS CAPABILITIES: Remember that global APRS messaging is just a small part of the overall local and Global APRS objective of providing local real-time situational awareness and connectivity for the exchange of pertient information among amateur radio operators.

  • Local situational awareness (APRS position reporting)
  • Local/Global Message capability by callsign (this page)
  • Mobile display of locally recommended voice frequency for travelers.
  • Ability to check-in and do basic functions from any DTMF radio (APRStt)
  • Ability to use thousands of DTMF Messaging radios (FT-51R and TH-78A)

    TRAVELERS VOICE REPEATER FREQUENCY OBJECTS: . All of the above APRS messaging devices should also be able to receive and display amateur radio information of immediate value. The most important of which, is the FREQUENCY of the nearest locally recommended voice repeater for travelers and visitors. . Since 2004 we have been encouraging this Local Info Frequency Initiative for the best recommended voice repeater and other RF assets of value to the traveler such as the local IRLP, EchoLink, and Winlink frequencies, or NET times or meetings in progress, etc as shown here.

    Notice how the IRLP and ECHOLINK nodes identify not only their node numbers and callsigns, but also their Tone, Range and status. (Bsy, Rdy, Lnk etc)... By pressing the OK button to see the POSIT screen, you can see that the Echolink node is 17.1 miles to the Southwest. [these photos were taken before we noticed that the Freqeuency on the second line was missing!]

    APRS is a two-way local Information Distribution and Communication System (not just a vehicle tracking system). See APRS misconceptions! . The objective is Human-to-human local real-time info and communications! .

    TRACKERS ARE TWO-WAY-TOO: . Even transmit-only APRS trackers should be configured to facilitate two-way human communications. . The RECEIVER should be tuned to a desired voice communication calling channel with this frequency information placed into the beacon text of the tracker. . This way, all who see the tracker can also establish contact with the operator. . Often this can simply be the Voice Alert frequency.

    HANDHELD DATA ENTRY:   While we are talking about overlooked capabilities,... Not only can these radios, cell phone and laptops convey messages and frequencies, but they also make excellent data entry devices in the field for amateur radio at special events. (and not just position and messages!). See HANDHELD data entry at a scout event.

    Bob, WB4APR