Spectrogram

A spectrogram is a visual representation of the spectrum of frequencies of a signal as it varies with time.

Online Tools

• Spectrum Analyzer

  Display a spectrum of signal amplitudes on different frequencies. Upload audio file like .wav or .mp3, .ogg.

• Spectral Analyzer

• Morse Code Adaptive Audio Decoder

Using Audacity

Audacity is an audio editor which also can be used for decoding signals in audio files.

1. Open an audio file in Audacity.

2. Click the name of the file at left menu (which contains the reverse triangle icon).

3. In the drop-down menu, check Spectrogram.

4. If you want to edit advanced settings, click Spectrogram Settings in the menu and edit values.

5. Click Play button.

Using Inspectrum

Inspectrum is a radio signal analyzer for .cf32, .cf64, etc.

Using Rtl-433

rtl-433 decodes radio transmissions from devices on the ISM bands.

# -A: Pulse analyzer.
rtl_433 -A <file>