OnAirGeneral & tools · Experimental
Decode Spectrum analyser with an SDR
OnAir receives Spectrum analyser. Wide sweeping spectrum analyser (1 - 6000 MHz in about a second with a HackRF): live, peak-hold and averaged traces, waterfall, markers, band overlay, CSV export.
What Spectrum analyser is
The spectrum analyser sweeps a wide range quickly, with peak hold, averaging, markers and a band overlay.
Frequencies and where it is used
Wide sweeps, 1 - 6000 MHz in about a second with a HackRF (its native sweep), stepped retuning on other radios.
In OnAir the tuning shortcut is Sweep, 1 - 6000 MHz; you can enter any frequency your radio reaches.
What OnAir shows for Spectrum analyser
Live, peak-hold and averaged traces, persistence, waterfall, markers, EU band overlay, spur removal, CSV export.
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 mode sits at a high frequency, so check that your radio tunes it: a HackRF covers 1 MHz to 6 GHz, and RTL-SDR stops near 1.7 GHz. Some modes at these frequencies also need a fast radio (10 to 20 Msps) or a dish and an LNB.
Questions about Spectrum analyser
Can I decode Spectrum analyser with an RTL-SDR?
Probably not: an RTL-SDR tunes up to about 1.7 GHz. A HackRF (1 MHz to 6 GHz) or another wideband radio is the usual choice for this frequency range.
Is it legal to receive Spectrum analyser?
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 Spectrum analyser 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.