|
US2055174A
|
|
Multielement cathode ray tube
|
|
US1987686A
|
|
Electronic receiver for disk transmitters
|
|
US2049911A
|
|
Photoelectric system for multiplying and translating electrical impulses
|
|
US2005425A
|
|
Regenerative sound recording device
|
|
US1893291A
|
|
Volume control apparatus for recording and broadcasting
|
|
US2033476A
|
|
Regenerative sound recording device
|
|
US1938184A
|
|
Regenerative photo-electric cell
|
|
US1759581A
|
|
Method and apparatus for recording and reproducing sound waves
|
|
US1759580A
|
|
Apparatus for and method of photographically recording sounds
|
|
US1708476A
|
|
Apparatus for and method of recording and reproducing sounds
|
|
US1781550A
|
|
Method of and apparatus for recording and reproducing sounds
|
|
US1880020A
|
|
Regenerative photo-electric cell circuit
|
|
US1795089A
|
|
Sound-reproducing instrument
|
|
US1748515A
|
|
Sound-reproducing instrument
|
|
US1683980A
|
|
Combined safety razor, hair trimmer, and comb
|
|
US1647833A
|
|
Holder for telephone receivers
|
