GB622838A - Improvements in or relating to tunable apparatus - Google Patents
Improvements in or relating to tunable apparatusInfo
- Publication number
- GB622838A GB622838A GB29124/46A GB2912446A GB622838A GB 622838 A GB622838 A GB 622838A GB 29124/46 A GB29124/46 A GB 29124/46A GB 2912446 A GB2912446 A GB 2912446A GB 622838 A GB622838 A GB 622838A
- Authority
- GB
- United Kingdom
- Prior art keywords
- frequency
- oscillator
- mixed
- frequencies
- sum
- 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
- 238000010009 beating Methods 0.000 abstract 1
- 239000013078 crystal Substances 0.000 abstract 1
- 230000004048 modification Effects 0.000 abstract 1
- 238000012986 modification Methods 0.000 abstract 1
- 230000010355 oscillation Effects 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
- H03B21/00—Generation of oscillations by combining unmodulated signals of different frequencies
- H03B21/01—Generation of oscillations by combining unmodulated signals of different frequencies by beating unmodulated signals of different frequencies
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
- H03J3/00—Continuous tuning
- H03J3/02—Details
- H03J3/10—Circuit arrangements for fine tuning, e.g. bandspreading
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/06—Receivers
- H04B1/16—Circuits
- H04B1/26—Circuits for superheterodyne receivers
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Noise Elimination (AREA)
- Superheterodyne Receivers (AREA)
Abstract
622,838. Valve generating circuits; valve superheterodyne circuits. PHILIPS LAMPS, Ltd. Sept. 30, 1946, No. 29124. Convention date, May 25, 1943. [Classes 40 (v) and 40 (vi)] Tunable apparatus such as a radio transmitter or receiver has its frequency determined by the sum or difference of two frequencies, one of which is tunable in steps and the other continuously over a number of at least two different frequency bands having the same width, the frequency being selected so that interference due to higher harmonics is substantially avoided. Fig. 1 shows the application to a superheterodyne receiver. Signals in the range 1.5-22.5 Mc/s. are applied to the H.F. stages 2 and to the mixer stage 3. The local oscillator 8 which is preferably crystal controlled is adjustable in 1 Mc/s. steps from 0-19 Mc/s., oscillator 9 is adjustable in a continuous manner over the frequency bands 2-3, 3-4, 4-5, 5-6 Mc/s. The two local oscillators are mixed in stage 10 to give the sum of their individual frequencies and the resultant passed through the band-pass filter 11 which is adjusted with the tuning of oscillators 8, 9. The resultant oscillation is mixed in stage 3 with the incoming signals to give an I.F. of 500 kc/s. Data is given showing how interference due to harmonics may be reduced. The tuning adjustment is preferably associated with a switch to ensure the correct combination for any given tuning frequency. In a modification, Fig. 2, three local oscillators are used. Oscillator 13 is continuously variable over the range 2-3 Mc/s and is mixed with oscillator 12 which has a frequency of either 20 or 22 Mc/s., the sum frequencies appearing at the output are mixed with oscillator 8 which can be switched in 1 Mc/s. steps from 0-20 Mc/s. The difference of these two frequencies is produced in mixer stage 10, the continuously variable frequency 22-23 or 24-25 Mc/s. exceeding the frequency of that of the resultant beating oscillator except for the one range 22-23 Mc/s., where the two are equal.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL622838X | 1943-05-25 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB622838A true GB622838A (en) | 1949-05-09 |
Family
ID=19788476
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB29124/46A Expired GB622838A (en) | 1943-05-25 | 1946-09-30 | Improvements in or relating to tunable apparatus |
Country Status (4)
| Country | Link |
|---|---|
| BE (1) | BE455967A (en) |
| DE (1) | DE890816C (en) |
| GB (1) | GB622838A (en) |
| NL (1) | NL65280C (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3018439A (en) * | 1958-11-20 | 1962-01-23 | Gen Dynamics Corp | Automatic wave analyzer |
| EP1585227A1 (en) * | 2004-04-08 | 2005-10-12 | Frank Dr.-Ir. Op 't Eynde | A two-step frequency converter with only one mixer in the signal path |
-
0
- BE BE455967D patent/BE455967A/xx unknown
- NL NL65280D patent/NL65280C/xx active
-
1944
- 1944-05-23 DE DEN2223D patent/DE890816C/en not_active Expired
-
1946
- 1946-09-30 GB GB29124/46A patent/GB622838A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3018439A (en) * | 1958-11-20 | 1962-01-23 | Gen Dynamics Corp | Automatic wave analyzer |
| EP1585227A1 (en) * | 2004-04-08 | 2005-10-12 | Frank Dr.-Ir. Op 't Eynde | A two-step frequency converter with only one mixer in the signal path |
Also Published As
| Publication number | Publication date |
|---|---|
| NL65280C (en) | |
| BE455967A (en) | |
| DE890816C (en) | 1953-09-21 |
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