According to a first aspect the present invention is related to a head
drum arrangement allowing a much easier mounting of the rotary transformer. The
head drum arrangement comprises a non-rotating lower drum and a rotating upper
drum, which are connected by a shaft fixed in the lower drum. The upper drum is
mounted on the shaft by a bearing and preferably by two ball bearings. A rotary
transformer is arranged between the lower drum and the upper drum having a fixed
stator and a rotor rotating jointly with the upper drum. The rotor is non-positively
held in its position by the magnetic force of a permanent magnet accommodated in
the upper drum.
