7. The invention as set forth in claim 6 wherein said cathode ray tube means consists of a scan converter unit and a video monitor, triggerable flip-flip means operated by said second timing signal for providing control signals synchronous with the write/read period of said converter unit, and means for combining said last-named control signal and said first timing signals and operating said switch therewith such that the video input to said converter unit from said heterodyne detector is blanked during the read periods of said converter unit.
6. The invention as set forth in claim 5 wherein said analyzer also has a heterodyne detector, said apparatus including a first switch operated by said first timing signals for applying the output of said heterodyne detector to said cathode ray tube means only for the duration of said first timing signals to control the intensity of the display thereon whereby said display is blanked when said first timing signal is absent.