APPENDIX COLLINS RADIO CO., Mr. CHARLES F. DUCANDER, Executive Director and Chief Counsel, House of Representatives, Washington, D.C. Cedar Rapids, Iowa, April 27, 1961. DEAR MR. DUCANDER: Thank you for the invitation to submit a statement relative to the satellite communications systems hearings. The Collins Radio Co. is vitally interested in communication satellite systems, and has conducted extensive research applicable to this subject. Broad experience in communication systems, radio propagation, radio astronomy, astronautics, space electronics, ground-based systems for artificial satellite and space probe telemetering, and space communications has contributed to the company's interest and competence in this field. Three particular programs are especially germane to the central aspects of the present hearings: (1) The construction of the JPL-NASA deep space telemetering and tracking facilities at Goldstone, Calif., Woomera, Australia, and Johnnesburg, South Africa. This work was performed by the company and its systems subsidiary, the Alpha Corp. (2) The development and construction of communication systems for the NASA man-in-space program (Project Mercury) under subcontract from the McDonnel Aircraft Corp. (3) The Collins-sponsored communication satellite research performed by use of the NASA Project Echo passive communication satellite, ECHO I. Details of the first two programs are undoubtedly familiar to the committee, and will not be described further. The Collins-Alpha Project Echo research employed relatively modest antenna facilities, together with sophisticated electronic systems, to establish two-way communication links between Cedar Rapids, Iowa, and Richardson, Tex., by virtue of passive reflection by the NASA ECHO I satellite. The Cedar Rapids facility consisted of two 28-foot diameter steerable antennas, a 955 mc., 10-kilowatt transmitter, a special low-noise 810 mc. phase-lock receiver, and required auxiliary equipment. A photograph of the facility is enclosed. The Richardson facilities employed a 28-foot diameter antenna with a 10-kilowatt transmitter operating at 810 mc. and a 40-foot diameter steerable antenna fitted with a 955 mc. phase-lock receiver. Photographs of these facilities are also enclosed. 771 73254 0-61-pt. 2-13 These equipments were used in various combinations and modes of operation, employing various modulation procedures; to determine the basic feasibility of the passive reflection technique for communication systems, and to determine several system characteristics. Among the specific feasibility tests were the following: (1) Successful one-way live-voice transmission from Cedar Rapids to Richardson was first achieved utilizing the passive reflector on August 13, 1960, pass No. 11, at 1:15 a.m. c.s.t. (2) Successful FSK teletype transmission using the link was accomplished on pass No. 24, August 14, 1960, at 2:50 a.m. c.s.t. (3) Successful two-way live-voice communication was accomplished on pass No. 25, August 14, 1960, at 5 a.m. c.s.t. (4) Successful transmission of a facsimile photograph was accomplished using standard AP “FAX” terminal equipment. This occurred on pass No. 84, August 19, 1960, at 1:10 a.m. c.s.t. (5) Experiments were conducted and data recorded for the propagation study. These included: Two-way CW transmission, two-way tone modulation using modulating frequencies of 500 c.p.s., 1 kc., 2 kc., and side tone tests from Richardson to Cedar Rapids, using frequencies of 100 kc., 250 kc., 500 kc., 750 kc. A copy of three teletype transmissions is enclosed to show performance at three different signal levels. |