Before revision: Types of antique radio Morse receivers The first radio receivers used a coherer and sounding board, and were only able to receive CW continuous wave (CW) transmissions, encoded with Morse code (wireless telegraphy).
After revision: Types of antique radio Morse receivers The first radio receivers used a coherer and sounding board, and were only able to receive continuous wave (CW) transmissions, encoded with Morse code (wireless telegraphy).