maximum effective detection range on the order of . Work to improve these numbers was slow going, and the project was eventually relegated to purely experimental with no plans to introduce a service version. Post-war After VE day, all models earlier than the Mk. IIIG were declared obsolete, and ongoing work on many of the newer versions ended. In place of the entire series from Mk. VI to VIII came the Mark IX, which was essentially a version of the 3 cm Mk. VIII designed specifically for use on the E3/45 jet bomber, which after becoming B3/45, would finally emerge as the English Electric Canberra. In contrast to the earlier designs that were added to existing bombers in an external fairing, for E3/45 the radar was designed as an integral part of the aircraft. It was otherwise a relatively straightforward upgrade to the existing Mk. VIII with a much more powerful 200 kW magnetron and numerous other minor changes. A contract was awarded to EMI in 1946 as the Mark IX, but during development it was amended to also equip the much larger B14/46 bomber designs, the V-force. These were essentially identical to the original concept, but used the larger "whirligig" reflector and became the Mk. IXA. Using the larger whirligig reflector and a slotted waveguide allowed the angular beamwidth to be reduced to 1.5 degrees, a great improvement over the World War II models. The Mk. IX, later known as Mk. 9 when roman numerals were dropped, allowed the scanning rate to be set at 8, 16 or 32 RPM. Additionally, like the K-band models, the IX included the ability to perform a sector scan, limiting the movement of the scanner so instead of performing complete circles it scanned back and forth across a smaller angle. In this case, the idea was not to improve resolution but to provide much more rapid updates of the selected area, which was needed in order to account for the much higher speed of the aircraft. This was especially useful on the V-force, where the radar's location in the nose made it difficult to scan to the rear anyway, and at best some 60 to 90 degrees was always blocked. Further limiting the scan to 45 degrees, on-demand, was not a real loss. The system also added the ability to perform offset bombing, a relatively common addition to post-war bombing systems. It was