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-5OTA@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-5K7ABC-6 is on the air and you are now chasing

Your position report has to come from the same callsign and SSID that sent the message, W1XYZ-5 here and not W1XYZ or W1XYZ-9, and it has to arrive within 5 minutes. A beacon from any other station is logged as an ordinary position report and leaves your chase waiting. If nothing arrives in time, the OTA bot lets you know so you can try again:

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

At this point you are chasing the op. That means you have made half of a QSO. Now you need the host to confirm. See the full @callsign reference for rate limits and every reply it can send.

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, from the station running the op. QSL is a Q-code that means “I am acknowleding receipt”

K7ABC-6OTA@W1XYZ-5 QSL thx for the contact 73

Step 4 - OTA sends QSL to chaser

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

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

There has been a confirmed bidirectional exchange of callsigns and locations. The QSO is now complete and has been logged and scored on the website. Every point comes from a stamp, a named fact about the contact; see Stamps and combos for the catalog and what each one is worth. Your first confirmed QSO with a host during their op is the one that scores; repeat contacts in the same op are logged but earn nothing.

See the QSL reference for the confirmation’s rate limits and every reply it can send.