Radio-telephony applied to whale hunting

This article describes the equipment supplied to an Antarctic whaling company to enable the various ships to communicate with one another and with the shore headquarters. The equipment operates on a wave-length of 325 metres, the power of the transmitter being 50 watts. The receiver consists of one stage of high-frequency amplification followed by a detector and two note magnifiers. In the output stage there are two valves in parallel, thus enabling a loud speaker to be used. A daylight range of 100 to 120 miles is regularly obtained except when the ships are very close in to the land.