A partially guyed tower is a tower structure which consists of a free-standing basement, in most cases of concrete or of lattice steel with a guyed mast on the top. The anchor basements of the guyed mast can be on the top of the tower or on the ground.
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Use
Partially guyed towers can be used e.g. when a very high tower for FM and TV transmission is required, which should also carry antennas for directional radio services in a much lower height. In this cases the antennas for directional radio services are mounted on the top of the free-standing part of the tower, while the guyed mast on its top carry the FM and TV antennas. They can be also used in order to upgrade small stable towers (like watertowers) with a long antenna mast for FM and TV broadcasting. However their use is rare, and done only in some European countries.
Partially guyed tower with anchor basements on the top of free-standing tower
Guyed masts on skyscrapers or thicker towers are often guyed on the roof of the free-standing basement structure. In this case there is no major constructive difference of the guyed mast to a guyed mast on plain ground and the construction of the free-standing basement tower does not differ much from a tower of the same height without the mast on the top. The guyed mast of such constructions is usually less tall than the free-standing basement tower.
Partially guyed tower with anchor basements on the ground
Much more rarely and interesting under constructive details are partially guyed towers at which at least one basement of the guy anchors is on the ground. At such structures, the guyed mast on the top is in opposite to guyed towers with anchor basements on the top of free-standing tower much taller (in most cases taller than the basement tower) and it must be considered at its construction and maintenance, that the basement of the guyed mast is situated much more elevated than that of the anchor basements.
Not considered as partially guyed towers are guyed mast radiators, which stand on the top of a helix building, because a helix building is much smaller than the mast radiator on it. Such constructions the Mühlacker radio transmitter and the Ismaning radio transmitter.