GB362478A - Trunk communicating installation with harmless cross talk - Google Patents
Trunk communicating installation with harmless cross talkInfo
- Publication number
- GB362478A GB362478A GB23724/30A GB2372430A GB362478A GB 362478 A GB362478 A GB 362478A GB 23724/30 A GB23724/30 A GB 23724/30A GB 2372430 A GB2372430 A GB 2372430A GB 362478 A GB362478 A GB 362478A
- Authority
- GB
- United Kingdom
- Prior art keywords
- line
- speech
- talk
- cross
- currents
- Prior art date
- 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
- 238000009434 installation Methods 0.000 title 1
- 238000000034 method Methods 0.000 abstract 1
- 238000009877 rendering Methods 0.000 abstract 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M5/00—Manual exchanges
- H04M5/04—Arrangements for indicating calls or supervising connections for calling or clearing
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B3/00—Line transmission systems
- H04B3/02—Details
- H04B3/32—Reducing cross-talk, e.g. by compensating
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Computer Networks & Wireless Communication (AREA)
- Interface Circuits In Exchanges (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
362,478. Preventing overhearing. SIEMENS & HALSKE AKT.-GES., Siemensstadt, Berlin. Aug. 7, 1930, No. 23724. Convention date, Aug. 23, 1929. [Class 40 (iv).] Two methods are described for rendering the cross-talk between lines transmitting in opposite directions unintelligible. In Fig. 1, speech over one line causes a buzzer or other noise producer G1, G2 to be applied to the other line to mask the cross-talk currents by means of a relay or other switching arrangement R1, R2, which is rendered ineffective by means of apparatus A1, A2 when speech starts over the other line. In Fig. 2, the speech currents in one line are inverted as regards frequency by means of apparatus U, the lower side-band resulting from the modulation of a carrier frequency equal to the highest speech frequency being transmitted, so that the cross-talk currents in the other line, which are inverted only once, are unintelligible.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE538837T | 1929-08-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB362478A true GB362478A (en) | 1931-12-07 |
Family
ID=34122368
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB23724/30A Expired GB362478A (en) | 1929-08-22 | 1930-08-07 | Trunk communicating installation with harmless cross talk |
Country Status (4)
| Country | Link |
|---|---|
| DE (2) | DE538837C (en) |
| FR (1) | FR703983A (en) |
| GB (1) | GB362478A (en) |
| NL (1) | NL32155C (en) |
-
0
- NL NL32155D patent/NL32155C/xx active
-
1930
- 1930-08-07 GB GB23724/30A patent/GB362478A/en not_active Expired
- 1930-08-12 FR FR703983D patent/FR703983A/en not_active Expired
- 1930-08-22 DE DE1930538837D patent/DE538837C/en not_active Expired
- 1930-09-20 DE DE1930604196D patent/DE604196C/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE604196C (en) | 1934-10-19 |
| FR703983A (en) | 1931-05-08 |
| DE538837C (en) | 1931-11-19 |
| NL32155C (en) |
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