The output of the type CF-2BequiPQent is generally oonnected to the input of D channel of type CF-M equi~nt. TH-1/TCC-l Carrier Temnlnal Ecuipment: An electronic device operating in the audio frequency range, that provides two full teletype duplex channels plus one speech channe1. This chsnnelizationis accomplished by a system of hybrid COIIS and associated oscillators. CF-7 Hybrid Adaptor: A eystan of hybrid coils so arranged as to direct the outgoing and incoming signals to and from the texminal equipment TH-1/TCC-l. The equipment described above was developed by the Signal Cor~ to enable them to rapidly set up, over unfriendly terrain, telephone and teletypewritercircuits between rear and forward areas. The procurement for the installationof these equipments aboard ships presentedmany problems. Investigationof their availability revealed that they would have to be ~owred from the Army Signal Corps. Inasmuch as there was no information available to BuShips or the Terminal Island Shipyard conoeming installationof these equipments aboard ship, many phases of layout and installationdeSicm had to be based on assumptions in lieu of information that would normally be supplied by the manufacturer’s engineers. In view of the limited time available, experiments could not be performed to eubstentiateour assumptions. To further complicate this problem 88 Section XI