OnAirGeneral & tools · Experimental
Decode General receiver with an SDR
OnAir receives General receiver. Listen anywhere in the band: NFM, WFM (mono), AM, USB, LSB and CW, click the spectrum to tune, filter width, squelch, AGC, de-emphasis, S-meter and audio recording to WAV.
What General receiver is
A general receiver demodulates what you click on: NFM, WFM, AM, SSB and CW, with filter, squelch and S-meter.
Frequencies and where it is used
Anywhere the radio tunes, 2 Msps.
In OnAir the tuning shortcut is NFM / AM / SSB / CW; you can enter any frequency your radio reaches.
What OnAir shows for General receiver
NFM, WFM (mono), AM, USB, LSB and CW (BFO pitch) on a channel clicked on the spectrum, with draggable filter edges and width presets, squelch (level or automatic against the noise beside the channel), AGC, de-emphasis, S-meter, frequency steps and audio recording to WAV.
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
Any radio that tunes this range works. An RTL-SDR covers roughly 24 MHz to 1.7 GHz, and every other radio in the radio guide reaches it too. Antenna height and a clear view of the transmitter matter most.
Questions about General receiver
Can I decode General receiver with an RTL-SDR?
Usually yes for narrowband signals, as an RTL-SDR tunes roughly 24 MHz to 1.7 GHz at up to about 2.4 Msps. Wide signals such as TV channels need a faster radio, and OnAir says next to the source what the selected radio can do.
Is it legal to receive General receiver?
These tools only look at the spectrum and listen. Receiving is legal in most countries, but laws differ on what you may use the content for.
Can I try General receiver 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.