An experiment in transmitting speech by Pulse Code Modulation, or PCM, is described in this paper. Each sample amplitude of a pulse amplitude modulation or PAM signal is transmitted by a code group of ...

A coherent optical time-domain reflectometer (COTDR) using flexible all-digital orthogonal phase code pulse is proposed for distributed acoustic sensing. All-digital orthogonal phase code pulse with ...

So when I recently came across an early 1970s HP 7041A X-Y recorder while clearing out my parents’ attic, I knew that I just had to see if I could get it up and running again. What is the difference ...