THE 6C SURVEY OF RADIO-SOURCES .4. THE ZONE 67-DEGREES-LESS-THAN-DELTA-LESS-THAN-82-DEGREES, 0H-LESS-THAN-ALPHA-LESS-THAN-24H

The sixth Cambridge survey of radio sources covers most of the sky north of delta + 30-degrees with an angular resolution of 4.2 x 4.2 cosec delta-arcmin2 and reaches a limiting flux density of 160 mJy at 151 MHz in the present zone with completeness achieved at 400 mJy on the best maps and at about 800 mJy on the worst. This paper presents 172 pages of maps of a region 67-degrees < delta < 82-degrees, 0h < alpha < 24h together with a list of 5421 sources in the 1440 deg2 covered. The text outlines only essential details of operation and analysis specific to this zone, since the principles of the method used to gather data and produce maps from a non-tracking telescope operating at declinations other than the north celestial pole are fully described in Paper 11 of this series. The present zone spans the gap between the North Polar Zone of Paper I and the delta + 58-degrees-Zone of Paper III, overlapping the former over the range 80-degrees < delta < 82-degrees and the latter over the range 67-degrees < delta < 68-degrees, 05h25m < alpha < 18h17m.