GB575035A - Improvements in or relating to electric signalling systems - Google Patents
Improvements in or relating to electric signalling systemsInfo
- Publication number
- GB575035A GB575035A GB207844A GB207844A GB575035A GB 575035 A GB575035 A GB 575035A GB 207844 A GB207844 A GB 207844A GB 207844 A GB207844 A GB 207844A GB 575035 A GB575035 A GB 575035A
- Authority
- GB
- United Kingdom
- Prior art keywords
- telegraph
- cycles
- channel
- drag
- band
- 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
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems
- H04M11/06—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
- H04M11/062—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors using different frequency bands for speech and other data
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Meter Arrangements (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
575,035. Superposed telephony and telegraphy. STANDARD TELEPHONES & CABLES, Ltd. (International Standard Electric Corporation). Feb. 4, 1944, No. 2078. [Class 40 (iv)] [Also in Group XL] In a system in which a telegraph or other channel is superimposed on a telephone line, a band of a width not exceeding 300 cycles within the range 500-1800 cycles and preferably including 1500 cycles is allocated to the telegraph channel, this band being excluded from the telephone channel. In such a system, the narrow-band filters employed at the telegraph receiver produce a drag effect on the received signals which necessitates a precise adjustment of the reception level to ensure that the drag does not affect the telegraph relay. Fig. 5 shows a self-adjusting circuit in which the amplifier 4 and amplifier-detector 5 are controlled by negative feed-back from the diode portions of the valve 5 through rectifiercondenser circuits 11; 12 and 17, 18. The condensers charge quickly during a signal and discharge slowly on its cessation on account of the rectifiers, thus providing sufficient hangover to cover the drag period. The circuit 17, 18 has a longer time-constant than 11, 12 and is intended to deal with signals that are only slightly above the proper level.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB207844A GB575035A (en) | 1944-02-04 | 1944-02-04 | Improvements in or relating to electric signalling systems |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB207844A GB575035A (en) | 1944-02-04 | 1944-02-04 | Improvements in or relating to electric signalling systems |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB575035A true GB575035A (en) | 1946-01-31 |
Family
ID=9733193
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB207844A Expired GB575035A (en) | 1944-02-04 | 1944-02-04 | Improvements in or relating to electric signalling systems |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB575035A (en) |
-
1944
- 1944-02-04 GB GB207844A patent/GB575035A/en not_active Expired
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