41774259081336_page_73

41774259081336 | page 73 | https://thedailydialectics.com/pdfs/FIOA/41774259081336/41774259081336.pdf

(a) PICKWICK A single channel duplex ciphony system for use on land lines of music (program) circuit quality. It is intended for use on a special switched network, Speech is Delta moftulated at a sampling rete of 15,000 per second, Encypherment is by means of plain text auto-key ‘consisting of four…