Engineering topics
Publications and source records attributed to Johns, C. E..
The prototype X-band exciter testing has been completed. Stability and single-sideband phase noise measurements have been made on the X-band exciter signal (7.145-7.235 GHz) and on the coherent X- and S-band receiver test signals (8.4-8.5 GHz and 2.29-2.3 GHz) generated within the exciter equipment. Outputs are well within error budgets.
The development of an X-band exciter, for use in the X-Band Uplink Subsystem, was completed. The exciter generates the drive signal for the X-band transmitter and also generates coherent test signals for the S- and X-band Block 3 translator and a Doppler reference signal for the Doppler extractor system. In addition to the above, the exciter generates other reference signals that are described. Also presented is an overview of the exciter design and some test data taken on the prototype. A brief discussion of the Block 3 Doppler extractor is presented.
The development of the X-band exciter and Doppler extractor equipment for the X-band uplink was completed. Stability measurements were made on the exciter and Doppler reference signals and the results are presented.
To assure successful tracking of the four Pioneer Venus probes, it is necessary for the deep space station receiver operators to be familiar with the characteristics of the received signals. As an aid for training the operators for this mission, signal simulators have been developed which completely duplicate the probe signals. This article describes the method used for generating these test signals.
Phase shifter circuit adjusts the phase relationship between a locally generated reference frequency and a received RF signal applied to a phase-coherent detector. It is small enough to be integrated into a receiver subassembly and operates on command from remote control panels.
New frequency divider circuit can be synchronized over a wider input control frequency range, has greater phase stability, and is less sensitive to temperature changes than conventional synchronized oscillators. The new circuit uses the avalanche breakdown mode of operation of transistors.
S-band receiver exciter ranging subsystem Blocks IIB and IIIB
Frequency shifter subassembly using synchronized avalanche oscillator for Block IIB receiver exciter