A new harmonic slide screw impedance tuner for VHF-UHF frequencies uses a reduced overall length spiral slabline structure and three rotating carriages allowing reducing the linear size of the tuner from originally L=3/2 to a spiral length L=2RN of a cylinder with 2R diameter and a height H made up of N floors (example: F=100 MHZ, =300 cm, R=10 cm, N=10 floors of 2 cm each, yields a 2020 cm cylinder versus a 450 cm linear slabline; a core reduction of 450/20=23). The slabline stands vertically on the bench table surface and the carriages, including the tuning probes rotate and wind up and down around a vertical axis through the center of the spiral slabline, controlled by a rack-and pinion spiral arrangement on the edge of the spiral slabline. The rotation of the carriages controls the phase of GAMMA and the insertion of the tuning probes into the channel of the slabline controls its amplitude.

A new harmonic slide screw impedance tuner for VHF-UHF frequencies uses a reduced overall length spiral slabline structure and three rotating carriages allowing reducing the linear size of the tuner from originally L=3/2 to a spiral length L=2RN of a cylinder with 2R diameter and a height H made up of N floors (example: F=100 MHZ, =300 cm, R=10 cm, N=10 floors of 2 cm each, yields a 2020 cm cylinder versus a 450 cm linear slabline; a core reduction of 450/20=23). The slabline stands vertically on the bench table surface and the carriages, including the tuning probes rotate and wind up and down around a vertical axis through the center of the spiral slabline, controlled by a rack-and pinion spiral arrangement on the edge of the spiral slabline. The rotation of the carriages controls the phase of GAMMA and the insertion of the tuning probes into the channel of the slabline controls its amplitude.