for low-level bombing where the short local horizon limited the amount of territory visible on the display and would require guidance on smaller objects like particular buildings. The corollary of this improved resolution was that a K-band system would offer the same resolution as the X-band system with an antenna half the size. Such an antenna would fit on the Mosquito, and development of a scanner began. The Mosquito was already widely used for pinpoint target indicator operations, and fitting them with H2S would further increase their abilities. On 22 February 1944, the development group proposed rapidly fitting Mark IV to all Lancasters, and for higher-accuracy needs, developing either an X-band Whirligig, or a K-band with a smaller antenna. Instead, they were ordered to do both. The K-band work was given the name "Lion Tamer". The first test of the basic equipment took place on a Vickers Wellington on 8 May 1944, and Lancaster ND823 was equipped with the prototype Mark VI and flew on 25 June. However, a meeting on 16 June noted that the range of the K-band sets was not good, with tests in the US reaching only from altitude. Further, production was not ready for large-scale deliveries, and as Dee put it, "the present programme of 100 H2S Mark VI equipments should be regarded as an expression of faith." Several new features became part of the Lion Tamer effort. Due to the much higher resolution of the K-band signals, a new display was needed because the dot produced on the older display was too large and overlapped details on either side. A solution was found in the Type 216 display, which featured sector scan, which allowed the operator to select one of the eight compass rose points and the display expanded to show only that sector. This effectively doubled the resolution of the display. Meanwhile, work on the new mechanical computers for air navigation was progressing well. It was decided that the Mark VI should be able to connect to these systems. Eventually, all of these changes were rolled up into the proposed Mark VIII. During the late summer of 1944, as the post-D-Day operations bogged down, there was renewed interest in using the K-band system to detect tactical targets like tanks. Lancaster JB558 was fit with a 6-foot scanner and a K-band set and began tests at low altitudes between beginning in December 1944. The