21 March 2016

CIS 5 x MFSK-16 + BPSK 250Bd Hybrid modem (II)

Just to point out some interesting analogies with a similar MFSK-16 signal, heard in the latest days of the past September 2015.
That signal had the same MFSK parameters, 5 x 16 tones 10Bd 20Hz, but with FSK inserts each 10 seconds rather than the BPSK inserts seen in these days . SOM and EOM shows the same style. While the BPSK version has a fixed lenght of 21:05 minutes, the FSK version had a 33 seconds lenght and was repeated each 15 minutes.
One could say that the BPSK version seen in these days is a sort of evolution of the semptember FSK (test ?) version, but it's probably a speculation.

1 comment:

  1. http://www.udxf.nl/Russian-Intel-MFSK-PSK-19851kHz.mp3 Similar signal? Has same bandwidth, 5-tone idle (maybe flipped USB and LSB), a slower baud rate, and uses PSK instead of the FSK for the interruption of the data transmission.