Notebook, Ernest Mills training to become a Wireless Operator Merchant Navy

[Note book used during Ernest Mills during his training to obtain the Post Master General's Special Certificate to become a Wireless Operator in the war- time Merchant Navy. 46p. used. Bears title 'Practical notes on service advise'. Contains drawings, notes and circuit drawings of a quench gap transmitter, a marine charging board type 8, a 187 board, a quarter kW spark transmitter etc, and notes re equipment, 'maintenance of accumulators', testing, radio telegraphy etc. Also includes two Marconigrams and instructions on how to fill them in. 1940-1950. See also 1998-19 to 21]