Use two receivers or two decoders at once in OnAir

Several ways to do more than one thing at a time.

Several receivers (multi-SDR)#

Each receiver is a full decoder with its own sample thread, radio, mode, frequency, gains, results and scanner. A high-end computer is recommended, and lower sample rates help; the status bar shows the CPU load.

Click + in the strip at the bottom of the window (RX 1 | RX 2 | +). A warning reminds you that performance may limit what is possible.
In the new tab choose a different radio and a mode. A radio is claimed by one receiver at a time ("in use by RX n" in the list), except the test signal and files.
Press Start in each tab. Up to four receivers (RX 1 to RX 4).
Only one receiver plays audio at a time (the speaker button of a tab); the others are muted.
Closing a tab (x) stops its receiver, saves its results and releases the radio.

Limit: two receivers cannot run the same mode at the same time ("RX n already uses this mode"); different modes run side by side.

A second mode from the same capture#

Instead of a second radio, add a second mode from the same capture: the toolbar offers Second: <mode>, and its own tab, Second: <mode>, appears. OnAir checks the frequency and sample rate fit the capture and says why if not. Twelve more modes became usable as second decoder in 0.2.6.

Multi-channel TV and the general receiver (0.2.6)#

Multi-channel TV: decode two or three adjacent DVB-T / T2 channels from one wide capture (shown working on a 61.44 Msps capture).
General receiver: up to four channels from one capture, draggable on the spectrum, with per-channel recording.

Whole span (0.2.5)#

The narrowband HF modes (FT8, FT4, WSPR, RTTY, CW, PSK) and the digital voice modes (DMR, NXDN, dPMR, D-STAR, M17, P25) can decode every signal in the visible span instead of only the tuned one.