GB566556A - Improvements in frequency-modulation apparatus - Google Patents
Improvements in frequency-modulation apparatusInfo
- Publication number
- GB566556A GB566556A GB14059/43A GB1405943A GB566556A GB 566556 A GB566556 A GB 566556A GB 14059/43 A GB14059/43 A GB 14059/43A GB 1405943 A GB1405943 A GB 1405943A GB 566556 A GB566556 A GB 566556A
- Authority
- GB
- United Kingdom
- Prior art keywords
- change
- frequency
- coupling
- resonant
- circuit
- 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
- H03C3/10—Angle modulation by means of variable impedance
- H03C3/12—Angle modulation by means of variable impedance by means of a variable reactive element
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03C—MODULATION
- H03C3/00—Angle modulation
- H03C3/10—Angle modulation by means of variable impedance
- H03C3/12—Angle modulation by means of variable impedance by means of a variable reactive element
- H03C3/14—Angle modulation by means of variable impedance by means of a variable reactive element simulated by circuit comprising active element with at least three electrodes, e.g. reactance-tube circuit
Landscapes
- Oscillators With Electromechanical Resonators (AREA)
- Stabilization Of Oscillater, Synchronisation, Frequency Synthesizers (AREA)
- Inductance-Capacitance Distribution Constants And Capacitance-Resistance Oscillators (AREA)
Abstract
566,556. Frequency modulation. GENERAL ELECTRIC CO., Ltd., GAVIN, M. R., and HEATHCOTE, V. A. Aug. 27, 1943, No. 14059. [Class 40 (v)] In an oscillation generator comprising a primary resonant circuit coupled to a loaded secondary resonant circuit, the coupling between the two circuits is so chosen that a given change in the reactance of the primary circuit causes a maximum change in the resonant frequency of the system as a whole. As shown, the primary circuit L1, C1, C is maintained in oscillation by the valves V1, V2 and is coupled to the secondary circuit L2, C2 which is loaded by a resistance R2, e.g. an aerial. Both circuits are individually resonant at the same frequency. The coupling is so chosen that #M/R2 is equal to the square root of L1/L2, where # corresponds to the mean frequency and M is the mutual inductance of L1 and L2. The Specification shows mathematically that with this coupling the rate of change of oscillatory frequency with change of L1 or C1 is a maximum. The signal for effecting this change may be applied to vary the capacity of a condenser C in shunt to C1, or to vary the inductance L1. In a modification, Fig. 2 (not shown), the signal is applied as a variable voltage to the grids of the valves, which causes a variation in the inter-electrode capacities.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB14059/43A GB566556A (en) | 1943-08-27 | 1943-08-27 | Improvements in frequency-modulation apparatus |
| US549840A US2448177A (en) | 1943-08-27 | 1944-08-17 | Variable-frequency oscillator system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB14059/43A GB566556A (en) | 1943-08-27 | 1943-08-27 | Improvements in frequency-modulation apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB566556A true GB566556A (en) | 1945-01-03 |
Family
ID=10034248
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB14059/43A Expired GB566556A (en) | 1943-08-27 | 1943-08-27 | Improvements in frequency-modulation apparatus |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US2448177A (en) |
| GB (1) | GB566556A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR960109A (en) * | 1947-01-24 | 1950-04-13 | ||
| US2848611A (en) * | 1953-07-23 | 1958-08-19 | Collins Radio Co | Phase stabilization of r. f. amplifiers and oscillator circuits |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2234461A (en) * | 1937-07-03 | 1941-03-11 | Nat Television Corp | Method and apparatus for controlling the frequency band width of coupled circuits |
| GB551344A (en) * | 1941-08-16 | 1943-02-18 | Cossor Ltd A C | Improvements relating to the frequency control of thermionic valve oscillators |
| US2353204A (en) * | 1942-10-15 | 1944-07-11 | Rca Corp | Wave length modulation |
-
1943
- 1943-08-27 GB GB14059/43A patent/GB566556A/en not_active Expired
-
1944
- 1944-08-17 US US549840A patent/US2448177A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| US2448177A (en) | 1948-08-31 |
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