FR548664A - - Google Patents
Info
- Publication number
- FR548664A FR548664A FR548664DA FR548664A FR 548664 A FR548664 A FR 548664A FR 548664D A FR548664D A FR 548664DA FR 548664 A FR548664 A FR 548664A
- Authority
- FR
- France
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M1/00—Substation equipment, e.g. for use by subscribers
- H04M1/68—Circuit arrangements for preventing eavesdropping
- H04M1/70—Lock-out or secrecy arrangements in party-line systems
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
Publications (1)
| Publication Number | Publication Date |
|---|---|
| FR548664A true FR548664A (zh) | 1923-01-30 |
Family
ID=1538204
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| FR548664D Expired FR548664A (zh) |
Country Status (1)
| Country | Link |
|---|---|
| FR (1) | FR548664A (zh) |
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0
- FR FR548664D patent/FR548664A/fr not_active Expired