OnAirPagers · Experimental
Decode POCSAG with an SDR
OnAir receives POCSAG. POCSAG paging messages (512, 1200 and 2400 bd) on a 25 kHz channel.
What POCSAG is
POCSAG is the long-standing pager protocol (512, 1200 and 2400 baud) still used by hospitals, fire services and utilities.
Frequencies and where it is used
Pagers, 512-2400 bd.
In OnAir the tuning shortcut is Pagers, 512-2400 bd; you can enter any frequency your radio reaches.
What OnAir shows for POCSAG
POCSAG paging messages (512, 1200 and 2400 bd) on a 25 kHz channel.
This receiver is built from the published specification and checked end to end on simulated signals. It has had little or no testing on real transmissions yet, so reports and recordings on Discord are welcome.
Which radio you need
This is a shortwave mode, so the radio has to tune HF. An SDRplay, Airspy HF+ or an RTL-SDR in direct-sampling mode do that directly; with a HackRF an HF upconverter or a direct-sampling receiver is the usual route. A long wire or loop antenna matters more than the radio.
Questions about POCSAG
Can I decode POCSAG with an RTL-SDR?
An RTL-SDR can receive HF only in direct-sampling mode, which OnAir offers in its radio settings; results depend on the antenna. SDRplay and Airspy HF+ radios are better suited.
Is it legal to receive POCSAG?
Pager messages can contain private information, and some countries restrict listening to them. Check the rules where you live before you use this mode.
Can I try POCSAG in OnAir without a radio?
Yes. Most modes include a built-in synthetic test signal, so you can open the screen and try the controls before you own a radio.
Try it without a radio
OnAir includes built-in synthetic test signals for most modes, so you can open this screen, see the layout and try the controls before you own a radio. The Tour button walks you through the app.