this wavefrom, most likely used by Portugues Air Force, is derived by STANAG-4197 unless the 39-tone used for data and digital voice transfer (they use the second tone-library only). The positions of the preamble tones match the STANAG-4197 specifications:
as well as the modulation used in the sixteen channels match the S-4197 second tone library (75Bd DQPSK, 112.5Hz spaced):
These transmissions was heard on 11265.0, 15025.0, 17973.0 and 20477.0 KHz on USB.
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