GB298481A - Improvements in or relating to radio transmitting systems - Google Patents
Improvements in or relating to radio transmitting systemsInfo
- Publication number
- GB298481A GB298481A GB28841/28A GB2884128A GB298481A GB 298481 A GB298481 A GB 298481A GB 28841/28 A GB28841/28 A GB 28841/28A GB 2884128 A GB2884128 A GB 2884128A GB 298481 A GB298481 A GB 298481A
- Authority
- GB
- United Kingdom
- Prior art keywords
- valve
- coil
- tuned
- frequency
- 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
- 230000005540 biological transmission Effects 0.000 abstract 3
- 230000008878 coupling Effects 0.000 abstract 3
- 238000010168 coupling process Methods 0.000 abstract 3
- 238000005859 coupling reaction Methods 0.000 abstract 3
- 239000013078 crystal Substances 0.000 abstract 3
- 230000010355 oscillation Effects 0.000 abstract 3
- 238000013016 damping Methods 0.000 abstract 1
- 238000007689 inspection Methods 0.000 abstract 1
- 238000010079 rubber tapping Methods 0.000 abstract 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03B—GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS
- H03B5/00—Generation of oscillations using amplifier with regenerative feedback from output to input
- H03B5/30—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element being electromechanical resonator
- H03B5/32—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element being electromechanical resonator being a piezoelectric resonator
- H03B5/34—Generation of oscillations using amplifier with regenerative feedback from output to input with frequency-determining element being electromechanical resonator being a piezoelectric resonator active element in amplifier being vacuum tube
Landscapes
- Oscillators With Electromechanical Resonators (AREA)
Abstract
298,481. Westinghouse Electric & Manufacturing Co., (Assignees of Trouant, V. E.). Oct. 8, 1927, [Convention date]. Thermionic Modulating systems.-The frequency of the oscillations generated by a crystal-controlled or similar valve oscillator is modulated for the transmission of telephone or like alternating- current signals by means of a controllable impedance connected in shunt to the tuned plate circuit of the oscillating valve, the modulating-valve being connected across a part of said impedance. The invention is a development of that described in Specification 292,469. The grid circuit of the valve 1 includes a piezo-electric crystal 5 or other mechanical resonator for determining the mean frequency of the oscillations. The tuned plate circuit comprises a coil 11 and variable condenser 12, and the valve oscillates by virtue of the inter-electrode capacity coupling. A shunt across the tuned circuit comprises a coil 37 and a blocking-condenser 39, and a part of the coil 37 is included in the plate circuit of the modulating valves 30. As shown these comprise two parallel-connected valves with their grid circuit connected to the secondary coil of a transformer 33, the primary including a microphone 35, which may be at remote point. Signals thus vary the impedance of the shunt network, and so impose slight variations on the frequency of the generated oscillations. The system may be employed in picture transmission and television systems. The output from the tuned circuit 11, 12 may be taken by tappings to an harmonic producer 17, amplifiers 18, 20 and coupling 21 to an aerial 22. These are of usual type, except that the tuned inter-valve couplings may have their damping slightly increased. Other aerials may be energized at the fundamental or harmonic frequency by line wires 100. The Specification as open to inspection under Sect. 91 (3) (a) refers also to the transmission of telegraph signals by a key-controlled resistance connected across part of the coil 37. The oscillator may be of the Hartley type instead of being crystal-controlled. This subject-matter does not appear in the Specification as accepted.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US298481XA | 1927-10-08 | 1927-10-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB298481A true GB298481A (en) | 1930-01-08 |
Family
ID=21851199
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB28841/28A Expired GB298481A (en) | 1927-10-08 | 1928-10-08 | Improvements in or relating to radio transmitting systems |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB298481A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3040279A (en) * | 1958-03-17 | 1962-06-19 | American Radiator & Standard | Sensitivity adjustment |
-
1928
- 1928-10-08 GB GB28841/28A patent/GB298481A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3040279A (en) * | 1958-03-17 | 1962-06-19 | American Radiator & Standard | Sensitivity adjustment |
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