GB500883A - Improvements in dual tone radio telegraphy system - Google Patents
Improvements in dual tone radio telegraphy systemInfo
- Publication number
- GB500883A GB500883A GB22516/37A GB2251637A GB500883A GB 500883 A GB500883 A GB 500883A GB 22516/37 A GB22516/37 A GB 22516/37A GB 2251637 A GB2251637 A GB 2251637A GB 500883 A GB500883 A GB 500883A
- Authority
- GB
- United Kingdom
- Prior art keywords
- marking
- spacing
- controlled
- aerial
- receiver
- 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
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Transmitters (AREA)
- Mobile Radio Communication Systems (AREA)
- Circuits Of Receivers In General (AREA)
Abstract
500,883. Wireless signalling. FINCH, W. G. H. Aug. 16, 1937, No. 22516. Convention date, Sept. 3, 1936. [Class 40 (v)] In a radio telegraphy system marking and spacing signals are sent on different carrier frequencies which are heterodyned by a single oscillator at the receiver to produce different audio frequencies. As shown two crystal-controlled carrier sources A, B are coupled to the aerial 22 through pentode ampliers 14, 15 respectively which are normally biassed to cut-off by the application of negative voltages to their screen grids 34, 35 respectively. A relay 30 with marking and spacing positions controlled by a telegraph transmitter 23, connects a source 38 of positive voltage to one or other of the screen grids 34, 35 to energize the aerial with the marking or spacing frequency. At the receiver, Fig. 2 (not shown), a crystal controlled oscillator produces different audio frequency beats from the marking and spacing carriers, which are filtered, rectified and fed to the marking and spacing coils respectively of the receiving relay.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US99208A US2118917A (en) | 1936-09-03 | 1936-09-03 | Dual tone telegraphy system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB500883A true GB500883A (en) | 1939-02-16 |
Family
ID=22273583
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB22516/37A Expired GB500883A (en) | 1936-09-03 | 1937-08-16 | Improvements in dual tone radio telegraphy system |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US2118917A (en) |
| GB (1) | GB500883A (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2527547A (en) * | 1941-02-10 | 1950-10-31 | Int Standard Electric Corp | Self-contained radio guiding apparatus for mobile craft |
| FR957756A (en) * | 1944-07-21 | 1950-02-25 | ||
| US2459281A (en) * | 1945-01-08 | 1949-01-18 | Rca Corp | Two-way radio equipment for lifeboat service |
| US2491387A (en) * | 1945-05-03 | 1949-12-13 | Rca Corp | Frequency shift keying |
| US2421054A (en) * | 1945-06-15 | 1947-05-27 | Press Wireless Inc | Carrier-shift signal control circuits |
| US2658196A (en) * | 1945-11-19 | 1953-11-03 | Burnight Thomas Robert | Synchronizing system |
| US2505781A (en) * | 1946-01-07 | 1950-05-02 | Frank C Mallinson | Radio transmitting system |
| US2482112A (en) * | 1946-01-25 | 1949-09-20 | Howard W Johnson | Carrier shift keyer |
| US2568408A (en) * | 1947-05-17 | 1951-09-18 | Rca Corp | Frequency shift diversity transmission system |
| US3007043A (en) * | 1954-07-09 | 1961-10-31 | Itt | Automatic frequency control system |
| US3011023A (en) * | 1957-11-18 | 1961-11-28 | Gen Electronics Lab Inc | Frequency shift keyed signal converter |
-
1936
- 1936-09-03 US US99208A patent/US2118917A/en not_active Expired - Lifetime
-
1937
- 1937-08-16 GB GB22516/37A patent/GB500883A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US2118917A (en) | 1938-05-31 |
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