Your RF Cafe
February 1967 Electronics World[Table of Contents] People old and young enjoy waxing nostalgic about and learning some of the history of early electronics. Electronics World was published from May 1959 through December 1971. All copyrights are hereby acknowledged. See all Electronics World articles.
Here you are - portable satellite communications in the mid 1960s. I guess the definition of "portable" has changed a bit since then.
When one thinks of a satellite communications station, what usually comes to mind is a massive parabolic antenna coupled to a large structure housing a formidable complex of electronics. During the past couple of years, however, many companies have succeeded in putting together a highly sophisticated satellite communicator in a very small package. In many cases, these stations are capable of being transported by conventional cargo aircraft to the desired site and then being set up and placed into operation within a few hours by a crew of only half a dozen men. Such a typical station is the Mark V AN/TSC-54 Satellite Communications Link Terminal developed by Radiation Incorporated and shown in the photo.
The entire system consists of the antenna portion, which is capable of collapsing down into a small package on its own trailer; an electronics shelter containing all the operating equipment; and a lightweight 45-kW, 400-Hz diesel generator. Total over-all road weight, including crew and sufficient fuel for 72 hours of operation, is 12 tons, which, if desired, can be broken down into discrete 3-ton packages for air transport. Set-up by the six-man crew, time from arrival at the site to actual communications is two hours.
When the equipment is set up and under power, the operator must then locate a satellite. The problem of locking onto a satellite is intensified by the relatively narrow beam width of the antenna (0.3°) and by the fact that the ground terminal's exact location may be unknown. When the operator presses a button, the antenna begins to follow a programmed scan pattern very rapidly. Each satellite is identified by means of a coded beacon signal. If, during the antenna scan, the ground system intercepts a satellite beacon, a relay doses and an integrator (position memory) directs the antenna to the position where the signal was spotted. If the beacon signal is not detected within two minutes, the automatic scan is resumed. If it is detected, automatic tracking begins. The received beacon signature first identifies the particular satellite; then the ground operator selects the appropriate frequencies to be used for that satellite and proceeds to transmit and receive messages.