GB546168A - Improvements in frequency stabilising circuits for frequency modulation systems - Google Patents
Improvements in frequency stabilising circuits for frequency modulation systemsInfo
- Publication number
- GB546168A GB546168A GB8140/41A GB814041A GB546168A GB 546168 A GB546168 A GB 546168A GB 8140/41 A GB8140/41 A GB 8140/41A GB 814041 A GB814041 A GB 814041A GB 546168 A GB546168 A GB 546168A
- Authority
- GB
- United Kingdom
- Prior art keywords
- frequency
- generator
- valve
- resistance
- grid
- 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
- H03—ELECTRONIC CIRCUITRY
- H03C—MODULATION
- H03C3/00—Angle modulation
- H03C3/02—Details
- H03C3/09—Modifications of modulator for regulating the mean frequency
Landscapes
- Inductance-Capacitance Distribution Constants And Capacitance-Resistance Oscillators (AREA)
Abstract
546,168. Automatic frequency control. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. June 27, 1941, No. 8140. Convention date, June 27, 1940. [Class 38 (iv)] [Also in Groups XL and XXXVI] In a frequency-modulated radio transmitter, a thermionic reactance valve 30 used for modulating the oscillation generator 4 is also used to maintain constant the mean frequency of the generator by applying a correcting voltage to a grid 36 of the reactance valve 30. Oscillations are conveyed from the generator by a lead 57 to beat with oscillations from a standard generator 50, and the resulting beats are passed through a limiting valve 58 to a circuit comprising a small condenser 72 and a resistance 74 ; a rectifier 78 shunts the resistance 74 and the resulting D.C. voltage across the resistance 74 is fed through a smoothing circuit R3, C2 to the grid 36 of the reactance valve 30. The correcting voltage rises as the beat frequency rises, owing to the effect of the circuit 72, 74, and acts on the reactance valve in such sense that the mean oscillation frequency is kept constant. The signal is applied through a transformer 40 to another grid 46 of the reactance valve to give the desired frequency modulation.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US546168XA | 1940-06-27 | 1940-06-27 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB546168A true GB546168A (en) | 1942-06-30 |
Family
ID=21992329
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB8140/41A Expired GB546168A (en) | 1940-06-27 | 1941-06-27 | Improvements in frequency stabilising circuits for frequency modulation systems |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB546168A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2848610A (en) * | 1953-05-25 | 1958-08-19 | Vitro Corp Of America | Oscillator frequency control apparatus |
DE1140969B (en) * | 1960-09-30 | 1962-12-13 | Siemens Ag | Frequency control circuit for synchronizing an oscillator |
-
1941
- 1941-06-27 GB GB8140/41A patent/GB546168A/en not_active Expired
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2848610A (en) * | 1953-05-25 | 1958-08-19 | Vitro Corp Of America | Oscillator frequency control apparatus |
DE1140969B (en) * | 1960-09-30 | 1962-12-13 | Siemens Ag | Frequency control circuit for synchronizing an oscillator |
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