• Design and Performance of a New S-Band Transmitter

      Swartley, Richard H.; Eitel-McCullough, Inc. (International Foundation for Telemetering, 1965-05)
      This paper describes a telemetry transmitter designed for the 2.2-2.3 Gc band. Design philosophy followed to achieve minimum size, wide deviation capability, high reliability and high efficiency are discussed in detail. The paper presents extensive measured data to indicate achievement of design goals set by IRIG 106-60 and ARTC-34. Construction details of the transmitter are illustrated.
    • Design Considerations in Pre-D Receiving and Recording Equipment

      Swanson, E. E.; Defense Electronics, Inc. (International Foundation for Telemetering, 1965-05)
      Design factors to be considered in wide band Pre-D recording and playback equipment for usage in a versatile Pre-D system are presented. These design factors are introduced in a discussion of both the down-translator and up-translator. The mechanisms which produce spurious outputs from the up-translator and the effects caused by these spurious outputs are treated in detail. The extension of Pre-D techniques to FM Electronics equipment is covered.
    • Recent Developments Pertaining to Solid-State S-Band Transmitters

      Slone, Sam; Fjeldsteld, Norman B.; Monitor Systems (International Foundation for Telemetering, 1965-05)
      This paper discusses the performance of some recent R. F. power transistors as frequency multipliers and relates this information to their use in solid state V. H. F. and U. H. F. Telemetry Transmitters. The step-recovery diode is - similarly discussed. Both devices are shown to have great promise for ultimately lowering the complexity, size, and price of Solid State S Band and L Band Telemetry Transmitters.
    • Rocket Trajectory Analysis from Telemetered Acceleration and Attitude Data

      Cooper, Oscar L.; Research Foundation, Oklahoma State University (International Foundation for Telemetering, 1965-05)
      Double integration of the longitudinal acceleration of a sounding rocket is useful as a simple means of determining its trajectory. Reasonably accurate altitude calculations can be made by this method except when surface winds alter the launch angle of the rocket. Surface wind velocity corrections can be introduced to correct velocity and position information in the horizontal direction, but accurate wind correction data is difficult to obtain for all rockets. A special solar aspect sensor was designed to be used with a commercially available magnetic aspect sensor for rocket attitude determination. This attitude data allows the longitudinal acceleration to be broken more accurately into three vector components. A feasibility study of the aspect system was made using three Aerobee-150 rockets. A digital computer trajectory program was written to utilize aspect and acceleration data for trajectory analysis. It is evident that rocket attitude data is a useful supplement to the longitudinal acceleration data for trajectory determination. More accurate magnetic aspect data is necessary, however, to refine the longitudinal acceleration technique.
    • Application of a Telemetry System using DSB-AM Sub-Carriers

      Roche, A. O.; Dynatronics, Inc. (International Foundation for Telemetering, 1965-05)
      The advantages of the DSB-AM subcarrier for wideband telemetry requirements have been discussed in previous papers. The purpose of this paper is to consider the specific performance of an FM telemetry r-f link when modulated by a frequency multiplex of DSB subcarriers. The performance is evaluated by constructing an appropriate model of the subcarrier multiplex based on a predicted noise power spectrum at the r-f demodulator output. The model is used to specify the individual subcarrier amplitude values that constitute the baseband signal, which will modulate the FM transmitter. The carrier power required to produce a useful signal-to-noise ratio at the outputs of the individual subcarrier demodulators is considered in general. The relationship between the degree of transmitter deviation, receiver bandwidth and the carrier power is derived. The carrier power required for operation over typical test range distances is determined in terms of the appropriate variables. The performance of two specific examples is calculated to illustrate the use of the several formulae that are derived. The examples also serve to relate and compare the performance of the DSB system configurations to the more traditional applications. Finally, the advantage of using increased r-f bandwidth is discussed.
    • Frequency Modulation Error Calculation

      Nyre, Donald L.; Douglas Aircraft Company (International Foundation for Telemetering, 1965-05)
      In a frequency modulation process, small amplitude sidebands near the deviation limits are sometimes distorted or lost. The problems and expense of preserving these lessor sidebands are often great, and spectrum space must be reserved for them. To date there appears to have been no clear statement of their importance in terms of data accuracy. This paper presents a numerical calculation of the errors accrued in a demodulated signal after truncation of the FM spectrum obtained with sinusoidal modulation. It is shown that the error increases for decreasing bandwidth. Error is evaluated for several bandwidths, and relationships to power outside the band are noted. Applications include specification of bandwidth for a given error in demodulated signal. The use of a limiter is assumed.
    • Miniature Telemetry Transmitter

      Wiley, J. R.; Busch, W.; Langan, L.; M.C.D. General Electric Company (International Foundation for Telemetering, 1965-05)
      The increased use of L and S-Band for telemetry services in conjunction with the need for miniaturized equipment, points up the desirability for compact transmitter units. This report describes a miniature S-Band transmitter and its associated power supply. The design goals are presented together with a discussion of the technical approach used to meet the severe requirements. Illustrations and performance data are included for completeness.
    • TELTRAC, A Telemetry Tracking Acquisition Aid System

      Knowlton, Orin H., Jr.; Canoga Electronics Corporation (International Foundation for Telemetering, 1965-05)
      TELTRAC, A Telemetry Tracking Acquisition Aid System, was manufactured by Canoga Electronics Corporation for the National Aeronautics and Space Administration to augment and update the Project Mercury systems for Project Gemini. In addition, many of the components of the TELTRAC System have been supplied to retrofit and upgrade the original Project Mercury systems. The features of the TELTRAC System that are new in comparison to previously existing Telemetry Trackers are the TELAR II Antenna and the Model 3403 Receiver, which employs both cross-correlation and phase-lock techniques. The TELTRAC System design criteria and a system error analysis, with particular emphasis on multipath errors, are discussed in this article. The detailed design of the TELTRAC System, as well as its subsystems, is also presented.
    • Propagation Characteristics of the Space Channel

      Baghdady, Elie J.; ADCOM, Inc. (International Foundation for Telemetering, 1965-05)
      A discussion is provided of the propagation phenomena, and their associated disturbances, that have been observed to cause significant degradation of the performance of space instrumentation and communication links.
    • A Radiation Hardened L-Band Telemetry Transmitter

      Butler, Dan M.; Ling-Temco-Vought, Inc. (International Foundation for Telemetering, 1965-05)
      The advent of requirements for nuclear radiation hardened telemetering components is accompanied by numerous technological problems. Future vehicles may impose severe environmental problems on a telemetering transmitter, as well as the need for relatively high r. f. power output. This paper describes the development of a nuclear radiation hardened telemetry transmitter, designed for operation in the 1435-1535 MC/S band at a nominal 100 W average R.F. power. The development phases covered in the paper consist of (1) design and radiation test of three low power transmitter exciters, (2) design and test of three transmitters, including the 100 W power amplifier and circuit modifications as dictated by radiation test, and (3) change in selection of the final R. F. tube. The paper includes a description of the resultant developmental transmitter, some comments on the major radiation effects problems, and some of the considerations in the radiation test of the transmitter. The author concludes with current status remarks.
    • A New Approach to Solid-State Communicator Design

      Schoenwetter, H. K.; General Devices, Inc. (International Foundation for Telemetering, 1965-05)
      An electronic commutator is described which employs only two types of modules and is expandable one channel at a time. Either high or low level commutators can be constructed. Data input circuits are completely isolated from gating voltages. Power per channel is 10 milliwatts; volume, 0.4 cubic inch. Commutator modules are suitable for air/spacecraft environments.
    • A Meteor Burst Telemetry System for a Nuclear Lunar Power Plant

      Swisher, B. F.; Johnson, R. E.; Boeing Company (International Foundation for Telemetering, 1965-05)
      The meteor burst telemetry system to be described was conceived, designed, and developed as an Engineering Model. The telemetry system will be used to telemeter oceanographic data from an experimental instrumented ocean buoy to be moored at continental shelf depths on Cobb Seamount to shore facilities at Seattle, Washington. Cobb Seamount is located in the Pacific Ocean approximately 300 miles off the coast of the State of Washington. A general description of the telemetry system and its operational characteristics, which are dictated by the statistical characteristics of the meteor burst mode of propagation, is presented. This is followed by a more detailed description of equipment elements of the system. The developmental status, the results of a propagation path field test, and plans for additional tests are discussed. Development results to date are sufficiently encouraging to generate confidence in the utility of a meteor burst telemetry system for oceanographic data acquisition.
    • The Operational Pre-D for the Atlantis Missile Range

      Shollenberger, George D.; Defense Electronics, Inc. (International Foundation for Telemetering, 1965-05)
      This newly-developed receiving and predetection recording system currently being integrated into the Atlantic Missile Range should prove of considerable interest to the telemetry systems engineer. The system, designated TRKI-12, will become part of the familiar "Range Rehabilitation Program." The TRKI-12 is capable of handling up to twelve simultaneous telemetry signals of any known or projected telemetry format. Frequency-translation methods used enable recording and reproduction of high bit-rate PCM and other wide-bandwidth signals with minimum distortion. A wideband FM recording method gives true DC to 500-kc bandwidth recordings. The system incorporates a diversity reception and combining concept enabling optimum combination of telemetry data from diversity antenna systems without undesirable byproducts or need for special phase-correction. The description herein, which includes design constraints and limitations for a system of this type, should yield information of concern to the range user and should be especially useful in establishing efficient and economical range interfaces.
    • Analysis of FM/FM Transmission Line Distortion

      Mohnkern, Gerald L.; N.A.S.A. (International Foundation for Telemetering, 1965-05)
      An IBM 1620 computer was programmed to evaluate the effects which the variation of propagation velocity and attenuation in coaxial cables has on a frequency modulated carrier. For a nine mile length of RG-8A/U the distortion of 70kc modulation on a 1 mc carrier was severe, while for a 10 mc carrier the distortion was negligible. A typical system using 4, 6, and 9 mc carriers on a single cable was evaluated.
    • An Operational Test Instrument for PCM Bit Synchronizers/Signal Conditioners

      Cumings, R. G.; Davies, R. A.; Defense Electronics, Inc. (International Foundation for Telemetering, 1965-05)
      The application for a device which will effectively test a PCM bit synchronizer/signal conditioner is described. The general requirements for a bit synchronizer analyzer are listed and some of the problems in implementing these requirements are discussed, including some problems relating to PCM signal conditioners. A description of an instrument capable of performing the required measurements is given.
    • Evaluation of an Expanded FM/FM Baseband Structure

      Campbell, E. B.; Herbert, W. R.; Electro-Mechanical Research, Inc. (International Foundation for Telemetering, 1965-05)
      An experimental evaluation program was undertaken to investigate the feasibility of expanding the IRIG (Inter-Range Instrumentation Group) FM/FM baseband. The results of the evaluation indicate that with typical field equipment, three higher-frequency proportional-bandwidth channels can be added to the baseband while maintaining adequate system performance.
    • A Six-Channel Physiological Telemetering System

      Robrock, R. B., II; Ko, W. H.; Case Institute of Technology (International Foundation for Telemetering, 1965-05)
      A six channel FM/FM physiological telemetering system was designed to measure two surface temperatures, an internal temperature, the respiration rate, and position and muscle spasm of a paralyzed patient. Tunnel diode subcarrier oscillators operating from a constant-current source provided excellent temperature and long term stability while permitting a complete transmission package with size 0.6" x 2.5" x 2.5" and weight 15 gm. A compatible transistorized receiving system was also constructed.
    • Receiver Noise Factor

      Hildner, Ernest G.; National Bureau of Standards (International Foundation for Telemetering, 1965-05)
      The Institute of Radio Engineers definition of receiver noise factor is reviewed and adopted for this paper. The definition’s implications are explored. CW-and dispersed-signal source measurement techniques are discussed and the mathematical base for each method is displayed. The quantities which must be measured in each method are pointed out with the respective advantages and disadvantages. It is concluded that the dispersed-signal source measurement technique is simpler than the CW-signal source techniques considered in this paper.
    • Telemetering Physiologic Data from Athletes

      Rose, Kenneth D.; University of Nebraska (International Foundation for Telemetering, 1965-05)
      Employing a team composed of physicians, electrical engineers, and specialists in physical education, significant dynamic physiological data has been gathered by means of radiotelemetry from athletes undergoing strenuous effort, participating in team sports, and from spectators viewing football games. Using a transistorized A.M.-F.M. transmitter carried in a padded compartment strapped comfortably onto the low back and weighing 30 oz. complete, ECG, pulse, temperature and respiration signals have been transmitted for distances up to 500 yards. The multiple technical problems surrounding distance telemetering of physiological information during active and vigorous muscular effort are discussed. Somatic muscle interference, the most troublesome artefact in dynamic electrocardiography, has been successfully circumvented by instantaneous recording of data from the momentarily inactive subject. Application of computer techniques to the analysis of exercise electrocardiograms must await procedural improvement and standardization and collection of adequate data on which to base valid programming.
    • A Novel PMCM System for Geophysical Research

      Toney, P. A.; Walter, J. M.; Dynatronics, Inc. (International Foundation for Telemetering, 1965-05)
      The concepts leading to development of an inexpensive digital data acquisition system employing novel Pulse-Morse Code Modulation and providing accuracy comparable to that of PCM are discussed. The several system-level and circuit-level considerations permitting the complete elimination of separate signal conditioning equipment and receiving-site synchronization, recording and processing equipment are presented. Finally, there is a brief commentary on future applications of the device and suggestions for related work.