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Exchange messages

QSO is a Q-code that originally meant “I can communicate with”. Now, it’s widely used ham slang as a noun meaning a completed contact. Part of that completed contact is the acknowledgement of the receipt of a message from the other party, which is called a QSL.

A QSO (aka completing a contact) follows this pattern of exchange between the host, the chaser, and the OTA bot.

Step 1 - chaser initiates contact

W1XYZ-5OTACHASE K7ABC-6 greetings from mike
OTAW1XYZ-5Send a position report within 5 mins to chase K7ABC-6
W1XYZ-54003.25N11131.50W((<>)) aprsota.org/W1XYZ
OTAW1XYZ-5Now chasing K7ABC-6 DN40fb. aprsota.org/K7ABC/ops/3

The position report must be sent from the same callsign and SSID that sent the message. In this example that means W1XYZ-5 and not W1XYZ or W1XYZ-9. The position report must be received within 5 minutes. Beacons from other SSIDs will be ignored. That rule is about your own station. The host’s SSID is optional in the chase itself, so CHASE K7ABC finds the same op as CHASE K7ABC-6.

Heads up

When this handbook refers to a position report it means a native APRS position report with a valid latitude and longitude. These coordinates typically originate from a GNSS device. Position reports are often called APRS beacons. The OTA bot does not recognize gridsquares that you type into the messages you send. Many web based APRS services can send APRS messages but cannot send an APRS position report.

If the position report isn’t received in time, the OTA bot lets you know so you can try again:

OTAW1XYZ-5No beacon received. Send CHASE K7ABC to try again.

Once your position report has been received, you are chasing the op. That means you have completed your half of a QSO. Now it’s up to the host to confirm. See the full CHASE reference for more information and some shortcuts for the CHASE command.

Step 2 - OTA bot notifies the host

The OTA bot will now attempt to contact the host and tell them that you would like to complete a QSO. It will include the chasers location encoded as a maidenhead grid square. If there are many chasers at the same time, your message may not get through. It may take the host a while to respond to all the chasers who have initiated contact.

OTAK7ABC-6DE W1XYZ-5 DN40fb greetings from mike

Step 3 - host sends QSL

The host sends a QSL to the OTA bot. QSL is a Q-code that means “I am acknowledging receipt”

K7ABC-6OTAQSL W1XYZ-5 thx for the contact 73

The callsign is what tells the bot which chaser the host is answering, so a QSL always carries one. @W1XYZ-5 QSL thx for the contact 73 says the same thing with the call in front. The SSID on it is optional either way, so QSL W1XYZ thx for the contact 73 confirms the same contact.

Step 4 - OTA sends QSL to chaser

When the OTA bot receives the QSL from the host, it logs it for the website and passes it along to the chaser:

OTAW1XYZ-5DE K7ABC-6 QSL thx for the contact 73

There has now been a confirmed bidirectional exchange of callsigns and locations. The QSO is complete and has been logged and scored on the website. The QSO earns points from named facts about the contact. The Stamps and combos has the catalog and what each one is worth. Your first confirmed QSO with a host during an op is the one that scores points. Repeat contacts in the same op are logged but do not earn points.

See the QSL reference for more information.