radway turns an RTL-SDR USB receiver into a scanner on macOS: live spectrum and waterfall, band scanning that stops on activity, and audio the moment it locks on. This page covers what you need to run it and what to try when something is off.
Any USB stick built on the RTL2832U, including:
Coverage is roughly 24 MHz to 1.7 GHz. Receivers with a direct-sampling input
(the V4 among them) also reach the shortwave bands below 24 MHz — switch
SAMPLING to DIR-Q in Settings.
Unplug the receiver, plug it back in, then press REFRESH. If it
still isn't seen, try another USB port or a powered hub — some receivers draw
more than an unpowered hub will give. A receiver already opened by another SDR
application cannot be opened twice; quit the other app first.
Check the VOL slider, then SQUELCH: if the threshold
sits above the signal, audio stays muted on purpose. Squelch around −45 dBFS is a
sensible starting point. Also confirm the mode matches the signal — broadcast
radio needs WFM, most two-way traffic needs NFM, airband
needs AM.
Raise GAIN until the signal is comfortably above the noise, but
back off if it starts sounding harsh — an overloaded front end distorts. In
scanning mode, brief gaps are normal: the scanner re-sweeps whenever the signal
it is parked on drops below squelch. Turn off RESUME SCAN ON SIGNAL LOSS
in Settings to stay put instead.
That is the tuner's own local-oscillator leakage. OFFSET TUNING
in Settings moves it out of the channel; it is on by default.
Into the app's own Documents folder, inside its sandbox container:
~/Library/Containers/app.radway.scanner/Data/Documents/radway/.
Nothing ever leaves your Mac.
No. It is a receiver only — the hardware it drives has no transmitter.
Write to josterphone@gmail.com. Include your macOS version, which receiver you use, and what you were tuned to — that is usually enough to work out what is happening.