More on Jack's Naval Service Including Security Work

A letter I found in Jack's papers indicates that on March 20, 1945 he successfully completed a correspondence course on Communications with a mark of 3.83. (Germany surrendered on April 29. Japan did not surrender until Aug. 15, 1945).  However what is interesting about the letter is that at that time he was an officer in the Naval Reserve.  The letter was sent to Lt. John B. Leddy, S(E3) T, USNR, Naval Reserve Educational Center, Great Lakes, Illinois.  So, although it was a correspondence course, he took it at the center or at least received his mail at the center.  S(E3) is a USNR officer designation for Special Service, Special Engineering Duties, equivalent to EDO (Engineering Duty Only) Electrical.

I was wondering why Jack would be in the Naval Reserve and not in the regular Navy... he never mentioned this.  However, in recent years he had claimed that he had done secret work for the Navy.  It turns out that the Naval Reserve was very important in cryptographic work.   I recently found an interesting document online: "Silent Warriors: The Naval Security Group 1945-2005,"  According to this work, "of the more than 10,000 codebreakers who served in the U.S. Navy between 1941 and 1945, well over 90 percent were reservists. They played key roles in every aspect of what was then termed radio intelligence — interception, decryption, translation, and analysis — at sites around the world."  It is also mentioned that many of these reservists were not allowed to talk about their work and received no official recognition.  Jack insisted he was not allowed to talk about his work.  The document also says that these same reservists were kept on in this secret work during the period after WWII, i.e. during the Cold War.  My hypothesis is that Jack was in The Naval Security Group as a reservist doing security work from 1945 to sometime during the Cold War.  He could do this while maintaining a normal civilian life.  The document also states that:  "What operational work existed [during the period immediately after WWII]  was modest, and some was downright casual. Lacking proper drill sites and equipment, units organized “ham” radio efforts, monitoring frequencies (sometimes on Navy-supplied radios residing in reservists’ homes) and copying signals on frequencies assigned by CSA. For want of other options, the USNR allowed select members to conduct this classified work from home and send the results to Washington, DC, via registered mail.".

Jack's old friend Tom Nelson writes  "I am quite sure that after MIT he was sent on classified work to a Navy base in England and bases in various parts of the USA."  This looks like it was before the end of the war.