Equipment for interisland radio circuits

NEW equipment for the 4-step expansion and modernization program of the Hawaiian Telephone Company was procured, installed, and placed in service over a 3-year period.1,2 Standard commercially available radio and channelizing equipment was used for all of the new interisland circuits with, in some cases, minor modifications made to meet the operating requirements of the company. Fig. 1 of reference 1 shows the details of the installations. To achieve the highest possible degree of reliability, all but two individual radio links are equipped with stand-by radio transmitters and receivers. Fully automatic arrangements are provided to transfer from the regular to the stand-by equipment. In addition, stand-by engine generators will automatically start and assume the station load at all interisland radio station sites as well as carrier terminal locations. Centralized control and supervision from Honolulu of equipment located at remote radio sites has been achieved through a new type of control and supervision system originally engineered for the interisland network. This system is of particular interest because of its flexibility in application and because of the manner in which it provides for control and supervision of a large number of functions with relatively simple equipment and circuit arrangements, and with a minimum number of transmitted tones. Control and supervision systems are already in service on the Maui and Hawaii circuits. Additional equipment is presently being installed to replace existing supervisory control equipment on the Lanai and Molokai circuits. Future plans include equipping the two circuits to Kauai with a control and supervision system to replace equipment now in use.