GB531425A - Carrier current transmission systems - Google Patents
Carrier current transmission systemsInfo
- Publication number
- GB531425A GB531425A GB21254/39A GB2125439A GB531425A GB 531425 A GB531425 A GB 531425A GB 21254/39 A GB21254/39 A GB 21254/39A GB 2125439 A GB2125439 A GB 2125439A GB 531425 A GB531425 A GB 531425A
- Authority
- GB
- United Kingdom
- Prior art keywords
- pilot
- frequencies
- regulator
- attenuation
- changes
- 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
- H04B—TRANSMISSION
- H04B3/00—Line transmission systems
- H04B3/02—Details
- H04B3/04—Control of transmission; Equalising
- H04B3/10—Control of transmission; Equalising by pilot signal
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
- Transmitters (AREA)
Abstract
531,425. Automatic volume control. STANDARD TELEPHONES & CABLES, Ltd. July 21, 1939, No. 21254. Convention date, Sept. 28, 1938. [Class 40 (iv)] [Also in Group XXXV] In a carrier transmission system, a regulator arranged to introduce equal changes in attenuation at all frequencies is controlled by a pilot current of one frequency and a regulator arranged to introduce changes in attenuation which are different for different frequencies is controlled by a pilot current of a different frequency, a third regulator which introduces equal attenuation changes at all frequencies coming into action in an extreme position of the second regulator. As shown, a 92 Kc. pilot is picked off at 59, 60 and controls motor 11 in known manner to increase or reduce the flat loss introduced by a condenser potentiometer arrangement 5...10. A 140 Kc. pilot is picked off at 61, 62 and controls motor 19 to control condenser coupling arrangement 21 .. 29 which may have plates shaped to conform with any law to determine which of networks I ... VII shall be effectively in the transmission circuit. These networks all have the same loss at 92 Kc. and progressively greater losses at higher frequencies. When conditions are such that the insertion of network VII is unable to bring the 140 Kc. pilot to zero level, motor 19 brings in an additional flat attenuator in the form of a condenser device 13 ... 15. The roles of the pilots may be interchanged. Amplifier 31 may have a negative feed back path containing a frequency discriminating element.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US232095A US2172832A (en) | 1938-09-28 | 1938-09-28 | Carrier current transmission system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB531425A true GB531425A (en) | 1941-01-03 |
Family
ID=22871855
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB21254/39A Expired GB531425A (en) | 1938-09-28 | 1939-07-21 | Carrier current transmission systems |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US2172832A (en) |
| GB (1) | GB531425A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2449174A (en) * | 1942-04-13 | 1948-09-14 | Decca Record Co Ltd | Antenna supply phase and amplitude control |
-
1938
- 1938-09-28 US US232095A patent/US2172832A/en not_active Expired - Lifetime
-
1939
- 1939-07-21 GB GB21254/39A patent/GB531425A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US2172832A (en) | 1939-09-12 |
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