|
DE487385C
|
|
Circuit for tube devices
|
|
DE520799C
|
|
Contact microphone
|
|
DE537226C
|
|
Electrode system for discharge tubes
|
|
DE555776C
|
|
Circuit arrangement for the operation of electrostatic loudspeakers
|
|
DE466075C
|
|
Glow cathode
|
|
GB213216A
|
|
Improvements in and relating to electric motors for driving talking machines, dictating machines and the like
|
|
GB198662A
|
|
Improvements in and relating to variable electric condensers
|
|
DE389178C
|
|
Drive motor for speaking machines, dictation machines or the like.
|
|
DE464309C
|
|
Process for the production of curved diaphragms made of light metal for speech sets
|
|
DE328091C
|
|
Sound box for speaking machines
|
|
DE380448C
|
|
Process for separating alternating currents or for separating direct currents and superimposed alternating currents from one another
|
|
DE324645C
|
|
Circuit arrangement for electrical oscillating circuits
|
|
DE483947C
|
|
Glow valve tubes
|
|
DE486362C
|
|
Glow valve tubes
|
