The first book in the 3 book series I have is :

I think this link is to the entire book too.  In it you will find out about the fact that crystals were a mom and pop biz before WW II and the Army did not know how to relay a message until they learned how to do it from ham ops.  The reason for the handset mounted on the back of a Sherman is explained there too, and how AT&T in the middle 1930's, discovered the problem with crystals going bad that they did not tell anybody about until it was figured out again by someone else  late in the war..

The other 2 volumes were, 'The Test' and 'The Outcome'  I found this set about 12 years ago on the ABE books site, very inexpensive back then even them being the first printing, , but not so today.  All 3 are online.

Charlie, W4MEC in NC