BE403504A - - Google Patents
Info
- Publication number
- BE403504A BE403504A BE403504DA BE403504A BE 403504 A BE403504 A BE 403504A BE 403504D A BE403504D A BE 403504DA BE 403504 A BE403504 A BE 403504A
- Authority
- BE
- Belgium
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/02—Constructional features of telephone sets
- H04M1/19—Arrangements of transmitters, receivers, or complete sets to prevent eavesdropping, to attenuate local noise or to prevent undesired transmission; Mouthpieces or receivers specially adapted therefor
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Telephone Set Structure (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEN31436D DE568139C (de) | 1931-01-20 | 1931-01-20 | Schalldicht abschliessende Telefoneinsprache |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| BE403504A true BE403504A (en:Method) |
Family
ID=7345965
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| BE403504D BE403504A (en:Method) | 1931-01-20 |
Country Status (2)
| Country | Link |
|---|---|
| BE (1) | BE403504A (en:Method) |
| DE (1) | DE568139C (en:Method) |
-
0
- BE BE403504D patent/BE403504A/xx unknown
-
1931
- 1931-01-20 DE DEN31436D patent/DE568139C/de not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE568139C (de) | 1933-01-14 |