With Slutskin remaining the director, the new radio-location project was placed under Truten. Code-named Rubin, this system used an improved transmitter and receiver from Zenit, but had a single antenna, made possible by a device (a duplexer) personally developed by Truten. The times for determining coordinates were greatly reduced by displaying measurements on a cathode-ray tube. By August 1943, a prototype Rubin system was completed and transported to Moscow, where it was demonstrated in an anti-aircraft battery. While the Rubin was being developed, however, the USSR received a GL Mk II radar from the British. This was a well-tested, gun-laying system and was immediately reverse-engineered and placed into production, thus eliminating the need for the Rubin.