Winlink APRSLink
William McKeehan
William McKeehan
February 5, 2022

Winlink APRSLink

Winlink APRSLink


Send any characters to initiate login. The CMS will respond with a challenge consisting of three digits who's values represent positions of characters within your password. See 'RESP'.


This is a six character response to the login challenge. Respond with three password characters corresponding to the positions in the challenge plus three additional characters of your choosing (in any order). Example: Password is AbC123. Login challenge is: 425. You send '1b2Qz5'. AbZ21t would also be valid since it contains the characters 1, b, and 2 which correspond to the 4th, 2nd, and 5th character in your password.


Your login will expire after approximately two hours. You can manually log out anytime by issuing the "B" or "BYE" command.

Command Reference

Command Description
H or ? Return brief Help. Help is also returned whenever APRSLink does not understand a command. Use "?" followed by a command letter for detailed help for that command. Example: "?L" for help with the List command.
L Return a List of pending messages (a maximum of 5 are returned). The List command queries the Winlink e-mail server and builds a list of up to 5 recent messages. Other commands operate on this list of messages using the message number (#).
R# Read message number # (# is one of the numbered messages returned via the List command). Example: "R2"
Y# replY to message. Reply to message number # (# is one of the numbered messages returned via the List command). Example: "Y2"
SP This is a replacement for the "W" command (deprecated). It simplifies the sending of messages from APRS devices considerably. Here's the format: SP [email address, callsign, or alias] [subject] Then, anything you send to WLNK-1 other than /EX or the (P)layback command makes up the body of your message. If you mess up and need to start over, just issue a new SP command. Here's an example (all sent to WLNK-1): SP Test Message Some text for the body of the message. Some more text for the message. /EX Each line is a separate APRS message, but the need for entering specific commands for each line/message has been removed. You type and send as much text as necessary and then send /EX as a separate APRS message to complete your email.
/EX Complete and send the composed message. You should receive a confirmation message.
P Playback message. Play back message lines for the message being written.
SMS Send short message (one line). Syntax: SMS [email address, callsign, or alias] [message] Example: SMS A short message to Sam
A AL Create/update an alias for an e-mail address.Example: A Then use "SP sam" instead of "SP" To delete an alias omit the part after the equal sign. "A sam=" will delete the sam alias To get a list of all your aliases send "AL"
F# Forward message number # to address or callsign following F# (# is 1 to 5)(# is one of the numbered messages returned via the List command). Example: "F2"
K# Kill (mark as deleted) message number #(# is one of the numbered messages returned via the List command). Example: "K3"
G# Return information about closest active RMS Packet Gateway. # is a number indicating how many "close" stations are returned. The default (no #) is 1.
I Return Information about APRSLink

Here's how it works: You send an APRS message using WLNK-1 as the destination callsign with one of the above commands as the message text. APRSLink responds by sending APRS messages back to you via your IGate. Of course, your IGate must be configured to gate those messages back to RF - it should be.

Source::: APRSLink | Winlink Global Radio Email

Video from KM4ACK demonstrating the use of this service: Winlink with an APRS Radio | Alerts, send and receive Winlink messages with an APRS radio - YouTube