Inventor
BALLARD C RAY
US3 patents
Patents
3 patentsUS4425642AJan 10, 1984
Simultaneous transmission of two information signals within a band-limited communications channel
APPLIED SPECTRUM TECH586 citations96
US4425661AJan 10, 1984
Data under voice communications system
APPLIED SPECTRUM TECH278 citations96
US4433212AFeb 21, 1984
Telephone line interface circuit
APPLIED SPECTRUM TECH131 citations94