Interstitial channels for doubling TD-2 radio system capacity

The td-2 microwave radio relay system at present provides six broadband channels in each direction of transmission in the frequency band between 3,700 and 4,200 mc (megacycles), each channel being capable of transmitting several hundred voice circuits.1 This paper describes arrangements and some of the technical problems involved whereby the number of broad-band channels can be doubled with no significant penalty to the existing channels.