Time sharing jammers

1. A time sharing jammer comprising a plurality of sources of jamming signals, switching means, coupled to the plurality of sources of jamming signals, and to amplifier means for sending the jamming signals to the amplifier means, and a pseudo random code generator for generating a pseudo random bi-phase code arranged to cause operation of the switching means in accordance with the pseudo random bi-phase code and incorporating a clock pulse generator of a given period whereby any one of the plurality of sources of jamming signals is not coupled continuously to the amplifier means for longer than the period of the clock pulse generator.

2. A time sharing jammer according to claim 1 wherein the pseudo random bi-phase code comprises Manchester code.

3. A time sharing jammer according to claim 1 or claim 2 wherein the pseudo random code generator comprises a read only memory encoded with a random code.

4. A time sharing jammer according to claim 3 wherein the pseudo random code generator comprises a parallel serial converter for reducing the address change rate required of the read only memory.

5. A time sharing jammer according to claim 1 comprising at least two switching means for coupling the sources of jamming signals to at least two amplifier means and two or more pseudo random bi-phase code generators arranged to cause operation of the switching means associated with that generator, such that the period and the pseudo random bi-phase code for any pseudo random code generator is independent of the period and the pseudo random code for each of the other pseudo random code generators.