1,067,952. Transformers. H. KOLBE & H. KOHLER, [trading at BANS KOLBE & CO.]. Aug. 4, 1964 [Dec. 10, 1963; March 7, 1964], No. 31099/64. Heading H1T. [Also in Division H4] In an R.F. coupling device for supplying several like loads from a common source, a 1: 1 ratio transformer with a ferrite core 1 formed as a closed shell from two halves 1<SP>1</SP>, 1<SP>11</SP> is wound with a double conductor 2, which may be a coaxial cable, one end being taken to a terminal 5 and to earth and the other end to four terminals, two of which, 6, 6<SP>1</SP>, are connected to one conductor and the other two, 7,7<SP>1</SP>, to the other conductor. The supply is connected between terminal 5 and earth and the loads, each of which has the same impedance as that of the supply, to terminals 6, 6<SP>1</SP>, 7, 7<SP>1</SP> respectively and to earth. In this way, the joint impedance of the loads, i.e. two sets of two in parallel which are effectively put in series by the coupling transformer, is matched to the impedance of the supply (Fig. 3, not shown). In a second embodiment (Fig. 4, not shown) more than one load is paralleled on each terminal 6, 6<SP>1</SP>, 7, 7<SP>1</SP> but the joint impedance at each terminal is brought to the correct value, i.e. that of the supply, by a resistor in series with each load. In a third embodiment (Fig. 5, not shown) each terminal 6, 6<SP>1</SP>, 7, 7<SP>1</SP> is connected to a further 1: 1 transformer of the kind described above, thus multiplying the number of terminals for connection of loads by four, and this cascading may be continued further. The arrangements are stated to have broadband characteristics and to be suitable for operation over a range such as 150 kc/s. to 800 Mc/s.