Building 15. All HF (high frequency) transmitters, both Army and Air Force, were located in building 4; however, the personnel at this station were not integrated into a joint organization but operated as independent groups. d. Based on projected requirements for REDWING and the de- sire of the AEC to have radiotelephone service to Honolulu available during the build-up period, a single sideband radio system was installed in December 1954. The installation was made by an enlisted representative of the Signal Corps Plant Engineering Agmcy. It con- sisted of a T-409 Transmitter located in buildtig 4, an R-369 Receiver, AN/FTA-7 Radiotelephone Control Terminal and AN/FTA-6Volume Regulator,