Hosting and chasing APRS OTA from the Services tab
APRS OTA is an on-the-air activity run entirely over APRS, and APRS Connect gives it a screen of its own. Chasing works over APRS-IS, hosting needs a radio channel, and radio channels are part of APRS Connect Pro.
What APRS OTA is
APRS OTA (aprsota.org) sits on top of APRS. You announce an op, a session of roughly an hour, and operators anywhere try to reach you before the clock runs out. Each contact you confirm scores, and adds time. There are no summits, parks, or reference numbers: an op is hosted from wherever you are, and the exchange runs through the bot, callsign OTA, as ordinary APRS messages.
If you come from POTA or SOTA, expect different words. Nobody activates anything: a station hosts an op, chasers call it, and the host confirms each contact with a QSL. By the bot's handbook, an op runs for at least 60 minutes, gains 30 per STAY, and stops at two hours.
Where it lives in the app
APRS OTA is on the Services tab, the app's directory of APRS service bots, with a purpose-built screen of its own. Opening it asks what you want to do: Host an op or Chase an op.
The APRS OTA screen on the Services tab asks which side of the exchange you are on before it sends anything.
Hosting an op
One tap announces you on the air. The app sends HOST, with an optional free-text comment that chasers see in your spot, and the bot asks for a position report. The op starts when the bot confirms you are on the air, in a reply of the form N0CALL-7 is on the air from EM67wj. aprsota.org/N0CALL.
While the op runs:
- Callers arrive as cards showing their message and where they are calling from.
- Confirming a contact is one tap plus an optional note. The field under each caller is labelled "Say something back", and the note is included in the
QSLthe chaser receives. An empty note sends a bareQSL, which confirms just the same. - The screen shows your QSL count and the time remaining, with a STAY button that adds 30 minutes per press. When the bot answers that the op is at the two-hour maximum, the button goes away and a notice under the bar quotes the reply.
- END SESSION confirms, then sends
DONE, and the bot replies with your final score. If the clock runs out first, the bot closes the op itself, the screen says so, and noDONEis needed.
One timing detail: the bot only has a chase to confirm once the chaser's own position report has landed, which can be some seconds after their message reaches you. Confirm too early and it answers No chase from <callsign> to confirm; the contact stays on screen for another try.
Your ops, the logbook
Every op you host or chase is kept under Your ops, a logbook read back out of the OTA thread, with contacts, blasts, and the bot's own scores op by op. A final score comes only from the bot's Op complete line; when the bot has not stated one, the screen counts your own confirmations and says so.
Chasing from the other side
Chasing works from the other side of the same screen. The bot does not broadcast who is hosting, chasers ask it, so one tap sends CQ and the current list of hosts comes back as a message. If nobody is on, the bot says No ops on the air. Send HOST to start one.
From the list, hosts you have already worked this op are check-marked. Calling a host sends your chase message through the bot, which logs the contact for both of you. The default chase message is yours to edit, as a saved default and in the message box before each call. The host's page then tracks the exchange step by step: called, position report, registered by OTA, and finally the host's QSL back to you.
The position report is the bot's requirement: it asks for one within five minutes, from the same callsign and SSID that made the call. Once it lands, the bot relays your call to the host with your grid square and tells you Now chasing <host>.
The exact packet, on the button
The exact packet each action will transmit is shown on the button before you press it, the rule the rest of the service directory follows too: guided screens, with the raw APRS command there to inspect before it goes.
Defaults in Settings
Settings has an APRS OTA section holding the three texts the screen falls back on.
| Setting | What it does |
|---|---|
| Confirm message | Starts every QSL when you confirm a chaser. Each contact's box is still editable during the op; empty sends a bare QSL. |
| Host op comment | Fills the comment field when you go on the air. Change it on the host form when today's op has more to say. |
| Chase message | Starts the message box when you call a host. Still editable on the host's page before each call. Empty calls with a bare 73. |
Hosting needs a radio, and the bot enforces it
APRS OTA's rules require RF, and the bot checks. HOST is only accepted from a station transmitting over the air; one that arrives by internet is refused with Must transmit via RF to host. So the app sends HOST over RF only, never APRS-IS, and the same applies to QSL. Your HOST and the position report that follows have to be picked up off the air by a digipeater or an igate in range of your radio, or the bot never sees the request and the op will not start.
An APRS-IS connection is not enough for hosting. The app says exactly that on the screen and offers chasing instead, which works from RF or APRS-IS alike. To host, add a radio channel on the Radio screen (under More on the tab bar): Bluetooth TNC, Bluetooth LE TNC, USB TNC, Audio modem, or Network TNC. Every radio type appears on the Add channel sheet without Pro; choosing one opens the plans.
Where to read more
Chasing over APRS-IS is free; hosting needs a radio channel, and radio channels need APRS Connect Pro.
