GB590461A - Frequency modulated rotating radio beacon - Google Patents
Frequency modulated rotating radio beaconInfo
- Publication number
- GB590461A GB590461A GB1075/44A GB107544A GB590461A GB 590461 A GB590461 A GB 590461A GB 1075/44 A GB1075/44 A GB 1075/44A GB 107544 A GB107544 A GB 107544A GB 590461 A GB590461 A GB 590461A
- Authority
- GB
- United Kingdom
- Prior art keywords
- tone
- modulated
- frequency
- directional
- pattern
- 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
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S1/00—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith
- G01S1/02—Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith using radio waves
Abstract
590,461. Directive radio systems. BENDIX AVIATION CORPORATION. Jan. 19, 1944, No. 1075. Convention date, July 16, 1942. [Class 40 (v)] A rotating beacon comprises a non-directional radiation pattern frequency modulated with one tone and a rotating directional radiation pattern of substantially the same carrier frequency, frequency modulated with a second tone ; the modulations being keyed to provide a reference signal at a predetermined point in the rotation.. The directional pattern 3, Fig. 1, which is modulated at 1200 c.p.s., is arranged to be of greater strength than the non-directional pattern 2, modulated with 500 c.p.s., except over a small arc corresponding with the null of the cardioid pattern. The directional pattern is rotated at a uniform speed of 1 r.p.m. and the modulation of both signals is keyed with the code character N as the null of the directional pattern is at true north. Due to the limiter, a frequency modulation receiver produces an output of 1200 c.p.s. tone only for the whole of the beacon rotation with the exception of the small arc 5 about the cardioid null when the non- directional signal is stronger and 500 c.p.s. modulation is heard. The bearing of the receiver relative to the beacon is thus determined by observing the time interval between the reception of the " North " signal and the change in the modulation note, allowance being made for the fact that the tone changes slightly before the passage of the cardioid null. Apparatus for producing the radiation patterns is shown in Fig. 2. Carrier from oscillator 23 is frequency modulated at 24 with 1200 cycle tone from source 26 and fed to amplifier 33, 34 which supplies power in opposite phase over lines 48, 49 and slip rings 14, 15 to aerials 6 and 8 which are spaced one half wavelength apart on the turntable 9 which is rotated by the motor 10. The output from modulator 24 is also supplied to amplifier 51 which supplies power over line 65 and slip ring 13 to the central aerial 7. The length of line 65 is so adjusted that the energy in aerial 7 is in phase quadrature with that in aerials 6 and 8, and the resultant radiation pattern modulated with 1200 cycle tone is of cardioid form. Carrier from 23 or from a separate oscillator of somewhat different frequency, is also modulated with 500 cycle tone from oscillator 27 in modulator 25 and fed to amplifier 68 which also supplies power over line 65 to the central aerial to produce the non- directional radiation pattern. Mounted on the shaft supporting the turntable 9 is a keying disc 16 provided with conducting sectors 17, 77 and the annular contact ring 18, Fig. 3 (not shown), which co-operate with brushes 19, 20 to control the keying relay 22, the contacts 30, 31 of which connect the tone sources 26, 27 to the frequency modulators. At a predetermined point in the rotation of the aerial system contact between brush 20 and sector 77 is interrupted and upon,contimuation of rotation the sectors 17 and the brush 20 co-operate to open and close contacts 30, 31 in a manner forming the code character N, the slot of the N just ending as the null of the radiation pattern or the edge of the tone change region lies at true north. As an alternative to the mechanically rotated aerial system, two pairs of fixed spaced aerials in space quadrature may be employed, the energy fed to the two pairs being amplitude modulated at the desired rotation frequency to produce the rotating radiation pattern.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US451136A US2420605A (en) | 1942-07-16 | 1942-07-16 | Frequency modulated rotating radio beacon |
Publications (1)
Publication Number | Publication Date |
---|---|
GB590461A true GB590461A (en) | 1947-07-18 |
Family
ID=23790956
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB1075/44A Expired GB590461A (en) | 1942-07-16 | 1944-01-19 | Frequency modulated rotating radio beacon |
Country Status (2)
Country | Link |
---|---|
US (1) | US2420605A (en) |
GB (1) | GB590461A (en) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2528543A (en) * | 1944-09-06 | 1950-11-07 | Peterson Glen | Radio beacon system |
US2532939A (en) * | 1945-04-23 | 1950-12-05 | John W S Pringle | Radio beacon |
US2531453A (en) * | 1945-12-14 | 1950-11-28 | Standard Telephones Cables Ltd | Radio beacon system |
US2509230A (en) * | 1946-02-28 | 1950-05-30 | Standard Telephones Cables Ltd | Beacon system |
US2564703A (en) * | 1947-10-29 | 1951-08-21 | Sperry Corp | Omni-azimuth guidance system |
US2572041A (en) * | 1947-10-29 | 1951-10-23 | Sperry Corp | Selective azimuth signaling system |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2014732A (en) * | 1930-08-08 | 1935-09-17 | Rca Corp | Radio beacon system |
DE618512C (en) * | 1934-04-20 | 1935-09-11 | Lorenz Akt Ges C | Procedure for determining the location using a rotating radio beacon |
-
1942
- 1942-07-16 US US451136A patent/US2420605A/en not_active Expired - Lifetime
-
1944
- 1944-01-19 GB GB1075/44A patent/GB590461A/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
US2420605A (en) | 1947-05-13 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US3181159A (en) | Omnidirectional bearing system | |
US2253958A (en) | Rotating radio beacon | |
GB594532A (en) | Improvement in omnidirectional radio navigation-aiding systems | |
GB590461A (en) | Frequency modulated rotating radio beacon | |
GB563686A (en) | Detection system for very short waves, modulated in angular velocity | |
US2404501A (en) | Radio beacon system | |
US2490050A (en) | Navigation system | |
US2943323A (en) | Automatic direction finding device for aircraft | |
US2509230A (en) | Beacon system | |
US2471648A (en) | Equisignal radio beacon system | |
GB476215A (en) | Radio beacon system | |
US2804615A (en) | Navigational system | |
GB590491A (en) | Glide path radio beacons | |
GB467013A (en) | Improvements in or relating to directional radio systems | |
US2609534A (en) | Radio beacon | |
US3999187A (en) | Doppler VOR beacons | |
GB694549A (en) | Improvements in or relating to radio navigation | |
GB768109A (en) | Omnidirectional radio range system | |
GB535396A (en) | Improvements in radio transmitters | |
GB385521A (en) | Improvements in or relating to radio direction finding apparatus | |
GB734625A (en) | Improvements relating to speaking radio beacons | |
GB887619A (en) | Navigational aid systems | |
GB777055A (en) | Improvements in or relating to radio rotary beacon arrangements | |
US3004154A (en) | Phase wobbler | |
JPS55110968A (en) | Dsb doppler vor |