Abstract: A telescopic mast is provided in kit form with stays wound on reels in a predetermined order. This order is such that when erecting the mast it is only necessary to walk between the mast and pegs fixed into the ground and not between two pegs at a distance from the mast. This minimizes the amount of walking which is necessary in erecting the mast. Clamps between sections are formed from a strap around the outer of two concentric sections. The ends of the strap are secured together and attached to a member with a pressure face. A camming device between this member and the mast which acts against the pressure face and the mast enables the strap to be tightened thus gripping the outer mast portion against the inner mast portion. The top section of a telescopic mast is less inherent rigidity than the bottom section and this it is preferable to construct it from material with a greater resistance to longitudinal bending than the lower section and to vary the resistance of the intermediate sections accordingly.

Abstract: A logarithmic type of aerial array is formed of a plurality of similar broadband active aerial elements linearly arranged with logarithmic spacings, each aerial element being connected to a frequency-sensitive filter. The filters have progressive frequency-sensitive characteristics along the array such as to tend to pass higher frequencies where the elements are more closely spaced and lower frequencies where the elements are more widely spaced. The aerial elements are preferably each in the form of a loop, the impedance around the loop being increased in a region on the opposite side of the loop from the loop termination.