Subtle AFC locking difficulties in the X-band MQ bridge were identified. As a result, the electromechanical tuning of the X-band oscillator, the stability of the coupling of the LGR, the use of an external cavity AFC system, and modulation-type AFC techniques are being investigated. An X-band oscillator has been designed for use with the synthesizers that were procured. The oscillator has been partially fabricated, but final fabrication will be resumed upon completion of the electromechanical tuning investigation. The low noise amplifier in the X-band MQ bridge was upgraded. Noise measurements were repeated to confirm noise reduction expectations. The transmission paths between the housed portion of the bridge and the external precision phase shifters and attenuators were upgraded to a waveguide/coax assembly. This mechanical stiffening has eliminated """"""""cracked connector"""""""" problems. ?
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