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H04M1/00—Substation equipment, e.g. for use by subscribers
H04M1/64—Automatic arrangements for answering calls; Automatic arrangements for recording messages for absent subscribers; Arrangements for recording conversations
H04M1/65—Recording arrangements for recording a message from the calling party
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FR728902D1931-12-291931-12-29Dispositif d'enregistrement par amplification des sons et en particulier des conversations téléphoniques
ExpiredFR728902A
(fr)
Dispositif d'amplification des courants des cellules photo-électriques utilisées, par exemple, pour la télévision, la téléphotographie, les films parlants et la photométrie