Modes

CIS_500_FSK_Burst_Modem_SA_combo

Under the magnifier of Signals Analyzer: A Russian burst signal: FSK-2/1.000 Hz shift/500 bps

On these pages, you will find some information which should help you to identify a mode/modulation thanks to e.g.:

  • sonagram on HF Level
  • sonagram, spectrum, oscillogram on AF Level
  • sound (Audio)
  • speed [bps/Baud]
  • autocorrelation function [ACF]
  • modulation [e.g. MFSK-12 oder QPSK]
  • bandwidth
  • users, tips for decoding …

This landing page does list all signals according to some of their generic specifications – and not to their ITU-conform designation, like “100HA1AAN” for CW, or (some of their) names like STANAG 4285: Neither information would help you much in identifying an unknown signal. Thus, e.g. modulation, number of carriers, modulation scheme, bits per second (bps), autocorrelation function (ACF) are listed first. This provides the shortest way from a signal to it’s mode. A click on the first information will take you to the mode’s page with more specific Information.

STANAG 4285, e.g. is listed as:

  • PSK-8/2 (one carrier, phase shift keying, PSK-8 and BPSK modulation)
  • 2.400 bps (speed of 2.400 bits per second)
  • 106,67 milliseconds/ bit per second

Audio recordings had been mostly made with AGC Off to avoid any additional “modulation” by the receiver’s AGC. They are presented in the losless WAV format.

These information should help you also to identify signals by looking for appropriate candidates via the search function, top right on this page.