Very informative paper. I was intrigued by the mention of encoded morse code as the most reliable means of communication in areas with US jamming. Check out footnote 38.
38. In the author's own experience, Enigma-style crypto devices able to send secure messages letter by letter in Morse code automatically were in use in the Russian Navy as late as 1996.
It doesn't sound like the life expectancy was very long for anyone, especially a Badger recon crew.
Thanks for posting