HRO Receiver Was a Favorite of the “Y Service” in WWII

National HRO Receiver – photo from the Crypto Museum The Crypto Museum web site is worth a look –¬†https://www.cryptomuseum.com/ I am about a third of the way through “The Secret Listeners” and am enjoying it very much: The Secret Listeners by Sinclair McKay In the book, the receiver of choice for intercepting and decoding the enemy was the National HRO. The book goes into…