Moorhead VT-B with British B4 base cap. This was also known as the Type B transmitter. Most, if not all, were made for the British military.Thanks to Joe Gruber for sending the images.The balloon envelope is mm in diameter and, excluding the UV base pins, is mm tall.Reference: Joe Gruber. Type VT-B was first introduced in 1917. See also 1917 adverts. |