More than 50 years ago when I was on USS Intrepid CVS-11 we operated in the Norwegian and Barents Seas above the Arctic Circle.  I enjoyed using my Radio Shack pocket AM-FM radio from the starboard forward gun tub to listen to AM radio broadcasts from who-knows-where.

 

I think I was 30 years too late for u-boats (many still on the sea bottom below) to detect my radio's LO.  :-)

 

Mike / KK5F

(I still have that AM-FM radio.  I used it on all my later tours at sea...but only in port on my SSBN.)