|
GB306521A
|
|
Improvements in artificial lines for telegraphy and like purposes
|
|
GB232183A
|
|
Method of and apparatus for amplifying electric signal impulses
|
|
GB246193A
|
|
Improvements in or relating to means for generating signalling impulses for transmission over ocean cables and long land lines
|
|
GB203818A
|
|
Improvements in or relating to means for obtaining steady continuous currents
|
|
GB139497A
|
|
Improvements in or relating to electrically operated sound generators
|
|
GB139494A
|
|
Improvements in or connected with multi-step thermionic amplifiers
|
|
GB139496A
|
|
Improvements in or connected with receivers of high frequency sound waves
|
|
GB189411320A
|
|
Improvements relating to Telegraphic Transmission.
|
|
US519346A
|
|
Apparatus for telegraphic or telephonic transmission
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