A radio running OpenTX 2.3.0 or higher can use an internal or external MULTI-Module as a 2.4GHz spectrum analyzer.
The spectrum analyzer will show the strength of signals in the 2.4GHz band.
Long-press the SYS button to access the TOOLS menu
Scroll down and highlight the appropriate Spectrum option in the menu
Choose Spectrum (INT) for radios with an internal MULTI-module
Choose Spectrum (EXT) for radios with an external MULTI-Module
Press ENT to start the Spectrum Analyzer
The display shows frequencies on the 2.4GHz spectrum, from 2400MHz to 2480MHz. The X (horizontal) axis shows the frequency in MHz and the Y (vertical) axis shows relative signal strength.
F: Frequency at the center of the plot (fixed at 2440MHz) S: Bandwidth of the plot (fixed at 80MHz) T: Position of the cursor (vertical line)
Pressing ENT and scrolling left and right allows the T value to be changed, which will move the vertical line to highlight a specific frequency.