Aiming at a fast discrimination between charged pions and kaons in particle experiments, we are studying a compact threshold Cherenkov detector. The design and first experimental results are discussed. In the detector Cherenkov UV light is produced in a liquid C 6F 14 radiator in which a row of 2 cm diameter quartz tubes is immersed. Inside a tube, a wire is stretched along the axis as an anode, and parallel wires on the inner circumference function as a cathode. The light is detected in these tubes, which are filled with TMAE vapour.