GB556001A - Improvements relating to electrical communication systems - Google Patents
Improvements relating to electrical communication systemsInfo
- Publication number
- GB556001A GB556001A GB3374/42A GB337442A GB556001A GB 556001 A GB556001 A GB 556001A GB 3374/42 A GB3374/42 A GB 3374/42A GB 337442 A GB337442 A GB 337442A GB 556001 A GB556001 A GB 556001A
- Authority
- GB
- United Kingdom
- Prior art keywords
- carrier
- sub
- wave
- signal
- modulated
- 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
- H04B14/00—Transmission systems not characterised by the medium used for transmission
- H04B14/02—Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
- Near-Field Transmission Systems (AREA)
Abstract
556,001. Wireless and like signalling. STANDARD TELEPHONES & CABLES, Ltd., CHATTERJEA, P. K., and AMBROSE, D. M. March 13, 1942, No. 3374. [Class 40 (v)] Modulation is effected by varying the waveform of a sub-carrier or carrier wave, in accordance with a signal voltage. A sine wave of a sub-carrier frequency higher than is contained in the signal is applied at 3, 4 to the grid of a valve V2, and the signal voltage is applied at 1, 2 to the grid of a valve V1. The two valves have a common anode load resistance 17, across which is developed a sub-carrier wave modulated in amplitude. The peaks and troughs of this wave are cut off by oppositely-connected biased diodes V3, V4 giving at the output terminals. a wave which varies in form between a pure sine wave and a sloping-sided pulse as shown in Fig. 3. This wave is modulated on to a carrier at the terminals 5, 6 of a radio transmitter. At the receiving station the sub-carrier, after detection, is passed through limiters to a filter which rejects the fundamental sub-carrier but passes its harmonics to an ordinary rectifying detector, from which the signal passes through a lowpass filter to the phones or other receiving instrument. Alternatively the received modulated sub-carrier may pass to a damped circuit tuned to the sub-carrier frequency. The oscillations thus produced in this circuit vary in amplitude with the voltage variations of the original signal. The Provisional Specification states that the carrier may be transmitted over a wave guide, and that the sub-carrier may be transmitted directly over a line.
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
BE476184D BE476184A (en) | 1942-03-13 | ||
NL67408D NL67408C (en) | 1942-03-13 | ||
NL136059D NL136059B (en) | 1942-03-13 | ||
GB3374/42A GB556001A (en) | 1942-03-13 | 1942-03-13 | Improvements relating to electrical communication systems |
US476072A US2489268A (en) | 1942-03-13 | 1943-02-16 | Electrical communication system |
FR939087D FR939087A (en) | 1942-03-13 | 1946-04-01 | Electrical communications systems |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB3374/42A GB556001A (en) | 1942-03-13 | 1942-03-13 | Improvements relating to electrical communication systems |
Publications (1)
Publication Number | Publication Date |
---|---|
GB556001A true GB556001A (en) | 1943-09-15 |
Family
ID=9757111
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB3374/42A Expired GB556001A (en) | 1942-03-13 | 1942-03-13 | Improvements relating to electrical communication systems |
Country Status (5)
Country | Link |
---|---|
US (1) | US2489268A (en) |
BE (1) | BE476184A (en) |
FR (1) | FR939087A (en) |
GB (1) | GB556001A (en) |
NL (2) | NL67408C (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2564769A (en) * | 1949-10-25 | 1951-08-21 | Rca Corp | Translating circuit |
US2929924A (en) * | 1955-02-21 | 1960-03-22 | Westinghouse Electric Corp | Radiation suppression circuit |
US2956153A (en) * | 1957-11-08 | 1960-10-11 | Sylvania Electric Prod | Electrical noise reduction techniques |
Family Cites Families (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1584327A (en) * | 1926-05-11 | Electric-wave transmission system | ||
US1564627A (en) * | 1920-03-31 | 1925-12-08 | Rca Corp | Wireless telegraph and telephone transmission |
US1678163A (en) * | 1923-12-29 | 1928-07-24 | Western Electric Co | Modulation |
US1655543A (en) * | 1924-04-18 | 1928-01-10 | Western Electric Co | Transmission system |
US1911253A (en) * | 1926-09-13 | 1933-05-30 | Clinton Dorothy | Radio receiving apparatus |
US1699570A (en) * | 1927-09-23 | 1929-01-22 | American Telephone & Telegraph | Carrier suppression modulation |
US1876793A (en) * | 1929-10-22 | 1932-09-13 | Frank C Talmadge | Radio circuit |
US1971383A (en) * | 1932-03-11 | 1934-08-28 | Telefunken Gmbh | Transmitter |
GB398853A (en) * | 1932-03-22 | 1933-09-22 | Marconi Wireless Telegraph Co | Improvements in or relating to radio and other high frequency modulated carrier wave systems |
US2061734A (en) * | 1934-09-29 | 1936-11-24 | Rca Corp | Signaling system |
US2279659A (en) * | 1937-04-13 | 1942-04-14 | Rca Corp | Frequency modulator |
NL88393C (en) * | 1937-06-18 | |||
US2205359A (en) * | 1938-06-24 | 1940-06-18 | Hygrade Sylvania Corp | Superheterodyne receiver |
US2230243A (en) * | 1938-06-28 | 1941-02-04 | Philip M Haffcke | Signal selection by amplitude discrimination |
US2257282A (en) * | 1939-04-27 | 1941-09-30 | Rca Corp | Frequency modulation of signals |
US2303493A (en) * | 1940-05-17 | 1942-12-01 | Rca Corp | Diversity signaling system |
US2404306A (en) * | 1941-04-01 | 1946-07-16 | Rca Corp | Communication system |
NL137118C (en) * | 1942-08-24 |
-
0
- NL NL136059D patent/NL136059B/xx unknown
- NL NL67408D patent/NL67408C/xx active
- BE BE476184D patent/BE476184A/xx unknown
-
1942
- 1942-03-13 GB GB3374/42A patent/GB556001A/en not_active Expired
-
1943
- 1943-02-16 US US476072A patent/US2489268A/en not_active Expired - Lifetime
-
1946
- 1946-04-01 FR FR939087D patent/FR939087A/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
BE476184A (en) | |
US2489268A (en) | 1949-11-29 |
NL136059B (en) | |
FR939087A (en) | 1948-11-03 |
NL67408C (en) |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
GB859002A (en) | Improvements in or relating to phase modulators for carrier communication systems | |
GB536383A (en) | Improvements in frequency modulation systems for radio signalling | |
GB651088A (en) | Electric pulse communication system | |
GB602846A (en) | Improvements in frequency or phase modulation detectors | |
GB587941A (en) | Improvements relating to multi-channel electrical pulse communication systems | |
GB562422A (en) | Frequency modulated pulse signalling | |
GB556001A (en) | Improvements relating to electrical communication systems | |
GB601129A (en) | Improvements in or relating to electric multi-channel pulse communication systems | |
GB661554A (en) | High frequency pre-emphasis for pulse code modulation | |
GB929025A (en) | Improvements in or relating to signal transmission systems | |
US3925736A (en) | Diode quad modulator with very high dynamic range | |
GB554914A (en) | Application of frequency dividers to the reception of signal modulated electric carrier waves | |
US2806136A (en) | Controlled modulation circuit | |
GB581731A (en) | Improvements in receivers for time modulated electrical pulses | |
GB555619A (en) | Improvements in electric signal transmission systems | |
GB606359A (en) | Frequency stabilising circuit for electric frequency modulators | |
GB898496A (en) | Improvements in or relating to speech-signal transmission systems | |
GB518433A (en) | Improvements in and relating to noise limiting circuits for communication or control systems | |
GB651115A (en) | Electric pulse communication system | |
GB945271A (en) | Muting circuit for signal-translating apparatus | |
GB604877A (en) | Method and means for the transmission of low frequency calls in telecommunication systems | |
GB1037543A (en) | Modulators and demodulators | |
GB620053A (en) | System for communication of electrical signals | |
GB591098A (en) | Improvements in or relating to high frequency electrical communication systems | |
GB533812A (en) | Improvements in or relating to interference suppressors for radio receivers |