Receives, transmits and regenerates data on two-pair transponder bus operating at 10.24 k baud; rejects up to 30 v transponder bus common-mode noise; oper pwr rqmts 9 to 30 vdc, 75 milliamps; o/a dims 6.5 in. W; 7.5 in. Lg; 1.0 in. D; mounts on flat surface at fixed ground installation