Magnetic wire recording History of sound recording

wire recording or magnetic wire recording analog type of audio storage in magnetic recording made on thin steel or stainless steel wire.

the wire pulled rapidly across recording head, magnetizes each point along wire in accordance intensity , polarity of electrical audio signal being supplied recording head @ instant. later drawing wire across same or similar head while head not being supplied electrical signal, varying magnetic field presented passing wire induces varying electric current in head, recreating original signal @ reduced level.

magnetic wire recording replaced magnetic tape recording, devices employing 1 or other of these media had been more or less simultaneously under development many years before either came widespread use. principles , electronics involved identical. wire recording had advantage recording medium developed, while tape recording held need improve materials , methods used manufacture tape.

magnetic recording demonstrated in principle 1898 valdemar poulsen in telegraphone. magnetic wire recording, , successor, magnetic tape recording, involve use of magnetized medium moves constant speed past recording head. electrical signal, analogous sound recorded, fed recording head, inducing pattern of magnetization similar signal. playback head can pick changes in magnetic field tape , convert electrical signal.

with addition of electronic amplification developed curt stille in 1920s, telegraphone evolved wire recorders popular voice recording , dictation during 1940s , 1950s. reproduction quality of wire recorders lower achievable phonograph disk recording technology. there practical difficulties, such tendency of wire become tangled or snarled. splicing performed knotting cut wire ends, results not satisfactory.

on christmas day, 1932 british broadcasting corporation first used steel tape recorder broadcasts. device used marconi-stille recorder, huge , dangerous machine used steel tape had sharp edges. tape 0.1 inches (2.5 mm) wide , 0.003 inches (0.076 mm) thick running @ 5 feet per second (1.5 m/s) past recording , reproducing heads. meant length of tape required half-hour programme 1.8 miles (2.9 km) , full reel weighed 55 pounds (25 kg).