What kind of strange device is this? Actually it is a quarter-wave coaxial impedance transformer/matching device that ties together four antennas to one cable for feeding into a radio receiver. This particular matching transformer is cut for the downlink frequency of MIST at about 437 MHz, so it is the firtst part we have got for the furture ground station of MIST! The square-crossection tube was bought from the garden supply store Bauhaus! This type of device is very well-known among radio specialists.