This is Photograph 111-SC-282168 U. S. Fifth Army Mobile Unit Programs Can Be Heard over Razor Blade Sets. 1945. Records of the Office of the Chief Signal Officer, Record Group 111. National Archives at College Park, College Park, Maryland. It is by far the best known photograph of a soldier with a foxhole radio at Anzio. It was taken for YANK magazine but never ran. 

The other photos in series with this one include the names of the subjects. But not this one. The note with the negative only gives the title. So far this soldier remains anonymous. I would prefer to include his name in the book, naturally, so if anyone recognizes him please let me know!