QRP: Low-Power Communications

arlier this year I had the pleasure of reading “The Paraset Radio: The Story of a WWII Spy-Radio and How to Build a Replica” by Hiroko Kato, AH6CY. This book gave me the inspiration to build my own spy radio (21 century kit form) for use at home and in the field. AH6CY mentioned in his book that the Four State QRP Group offered the Bayou Jumper transceiver, a kit that pays homage to the Paraset. The Bayou Jumper is two separate circuits, a crystal-controlled transmitter and a regenerative receiver, that are built on one board covering the CW segment of the 40-meter band. Switching between the receiver and transmitter is accomplished via a built-in rotary switch. The regenerative receiver is the same as used in the Paraset spy radios from World War II and uses a “spotting” function to help the user tune the receiver to the transmit frequency. The transmitter is Four State QRP Group’s NS-40 transmitter, which puts out 4-5 watts of power. This radio was designed to fit inside a wooden box that is readily available from Hobby Lobby. As a QRPer who started out in the hobby using a crystal-controlled Knight T-50 transmitter and a Drake 2-B receiver paired with a T/R switch to manually select between transmit and receive, I was excited to order this kit and relive some of my Novice days, but this time with a highly