CH214653A
(en )
1941-05-15
Device for reproducing magnetic sound recordings.
CH226051A
(en )
1943-03-15
Process for magnetic sound recording in dictation machines.
CH235527A
(en )
1944-12-15
Method of improving the sound insulation of solid walls.
CH225703A
(en )
1943-02-15
Method for selective weed control.
AT174746B
(en )
1953-04-25
Method for stereophonic sound transmission
CH225000A
(en )
1942-12-31
Method for dynamic control when transmitting sound events.
CH205323A
(en )
1939-06-15
Magnetic arc extinguishing method.
CH219703A
(en )
1942-02-28
Device for stereophonic sound transmission.
NL59483C
(en )
1947-06-16
Sound equipment.
FR872110A
(en )
1942-05-30
Transmission improvements
CH233314A
(en )
1944-07-15
Method for transmitting still images.
CH220047A
(en )
1942-03-15
Process for the preparation of an aryloxy-alkylamino-butanone.
FR844211A
(en )
1939-07-20
Improvements to sound reproducing devices such as loudspeakers
FR880733A
(en )
1943-04-02
Sound re-recording system
CA370343A
(en )
1937-12-07
Sound re-recording method
DK66590C
(en )
1948-04-12
Stereophonic audio transmission system.
DK66081C
(en )
1947-12-22
Stereophonic audio transmission system.
CH225775A
(en )
1943-02-28
Process for the production of zeolites.
CA371008A
(en )
1938-01-04
Sound record forming method
FR826282A
(en )
1938-03-28
Method for locating sound sources
CH211725A
(en )
1940-10-15
Frequency division method.
FR876083A
(en )
1942-10-13
Signal transmission method
AT174639B
(en )
1953-04-25
Circuit for multiple use of a transmission channel
CH229780A
(en )
1943-11-15
Method of gluing.
FI19636A
(en )
1943-08-14
Bookbinding method