High-power broadcasting transmitters at Budapest and Kalundborg

These two transmitters are built according to the same general design, the former being for 60 kW and that at Kalundborg for 120 kW. A distinctive feature of these stations is the form of construction of the power amplifier equipment, in that this apparatus, following the practice commonly adopted in the installation of indoor h.v. power plant, is installed in brickwork cubicles. Other points of special interest are the use of a small number of high-power valves in the last stage, each having a reserve valve in position which can cut in at a moment's notice; the use of high-efficiency mercury-vapour rectifiers for the h.v. d.c. supply; the reduction of the number of components and controlcircuits to an absolute minimum in the interest of reliability; and the elimination of rotating machinery, except for the single-filament machine and the water pumps, by the utilisation of dry metal rectifiers and hot-kathode mercury-vapour rectifiers for the low-power supplies.