GB555212A - Improvements in modulated carrier-wave communication systems - Google Patents
Improvements in modulated carrier-wave communication systemsInfo
- Publication number
- GB555212A GB555212A GB1708/42A GB170842A GB555212A GB 555212 A GB555212 A GB 555212A GB 1708/42 A GB1708/42 A GB 1708/42A GB 170842 A GB170842 A GB 170842A GB 555212 A GB555212 A GB 555212A
- Authority
- GB
- United Kingdom
- Prior art keywords
- indirect
- frequency
- wave
- television
- line
- 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
- 230000005540 biological transmission Effects 0.000 abstract 1
- 230000011664 signaling Effects 0.000 abstract 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/12—Frequency diversity
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N7/00—Television systems
- H04N7/12—Systems in which the television signal is transmitted via one channel or a plurality of parallel channels, the bandwidth of each channel being less than the bandwidth of the television signal
- H04N7/127—Systems in which different parts of the picture signal frequency band are individually processed, e.g. suppressed, transposed
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Multimedia (AREA)
- Computer Networks & Wireless Communication (AREA)
- Television Systems (AREA)
- Transmitters (AREA)
Abstract
555,212. Wireless signalling ; television. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. Feb. 9, 1942, No. 1708. Convention date, Feb. 7, 1941. [Classes 40 (iii) and 40 (v)J To avoid distortion in television and picture transmission due to the reception of indirect or reflected waves, the carrier frequency is charged periodically by synchronizing signals at the end of each line, or each frame or at the end of a determined number of lines or frames ; the frequency change being of such amount that the signals over the direct or desired path combine in their effect, while those over the indirect or undesired path do not so combine. With interlaced scanning, an odd number of lines is used, and the frequency change is made at the end of each line, so that the same line on successive frames is sent at different frequencies. When only one indirect or reflected path is in question, the two adjacent frequencies are so selected that the difference in length between the direct and indirect paths represents one half the mean wave-length, or an odd multiple thereof. Four carrier frequencies may be used in turn in such an order that changes from one frequency to the next adjacent frequency are avoided as far as possible. As shown, television signals applied at 1, 3 are amplified at 5 and modulate the radio transmitter 7. The synchronizing signals are separated at 9 and applied to a tripping-device I giving a rectangular output wave which changes the carrier frequency periodically. The rectangular wave may be derived from an oscillator which synchronizes the saw-tooth scanning wave. Specifications 402,629 and 474,682 ; and U.S.A. Specification 2,000,685 are referred to.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US377809A US2333245A (en) | 1941-02-07 | 1941-02-07 | Communication system |
Publications (1)
Publication Number | Publication Date |
---|---|
GB555212A true GB555212A (en) | 1943-08-10 |
Family
ID=23490599
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB1708/42A Expired GB555212A (en) | 1941-02-07 | 1942-02-09 | Improvements in modulated carrier-wave communication systems |
Country Status (2)
Country | Link |
---|---|
US (1) | US2333245A (en) |
GB (1) | GB555212A (en) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2498391A (en) * | 1945-03-22 | 1950-02-21 | Philco Corp | Television echo suppression system |
US2608616A (en) * | 1946-11-13 | 1952-08-26 | Bell Telephone Labor Inc | Facsimile system |
US2636937A (en) * | 1949-04-01 | 1953-04-28 | Rca Corp | Signal separating circuit for color television |
JP5663148B2 (en) * | 2009-06-29 | 2015-02-04 | アズビル株式会社 | Counting device, physical quantity sensor, counting method and physical quantity measuring method |
US8982336B2 (en) * | 2010-03-10 | 2015-03-17 | Azbil Corporation | Physical quantity sensor and physical quantity measuring method |
-
1941
- 1941-02-07 US US377809A patent/US2333245A/en not_active Expired - Lifetime
-
1942
- 1942-02-09 GB GB1708/42A patent/GB555212A/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
US2333245A (en) | 1943-11-02 |
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