A Slow-Scan TV System Using the Permachon for Scan Conversion

To satisfy a requirement of the U. S. Weather Bureau to view weather radar images many miles from the radar site, a system was developed which uses a slow-scan vidicon to convert an optical image of the radar display to a narrow-band television signal suitable for transmission over conventional telephone circuits. Scan-conversion equipment utilizing the Permachon storage vidicon converts the received slow-scan TV image to a bright 625-line TV display. The equipment cost is comparable to the cost of one possible alternative; a single hop microwave link and low brightness radar indicator. It is considerably less expensive than a microwave link plus bright display scan-conversion system. The slow-scan system has the further advantage that it can be used with a telephone circuit of any length, whereas a single microwave link is limited to about 30 miles.