a communications electronic warfare trainer that includes apparatus and a thod by which a training umpire can control the localized jamming of a victim communications system . a control signal containing an address and duration of jamming is generated and transmitted using the same frequency as the victim communications system . the control signal is processed by a receiver unit collocated with the victim communications system to determine if the control signal address matches the address of the victim communications system . if an address match is found , a jamming signal is produced for the specified duration causing disruption of the normal operation of the victim communications system .