US2131109A - Radio telegraph receiving system - Google Patents
Radio telegraph receiving system Download PDFInfo
- Publication number
- US2131109A US2131109A US682132A US68213233A US2131109A US 2131109 A US2131109 A US 2131109A US 682132 A US682132 A US 682132A US 68213233 A US68213233 A US 68213233A US 2131109 A US2131109 A US 2131109A
- Authority
- US
- United States
- Prior art keywords
- frequency
- detector
- circuit
- oscillator
- audio frequency
- 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 - Lifetime
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/02—Amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation
- H04L27/06—Demodulator circuits; Receiver circuits
- H04L27/063—Superheterodyne receivers
Definitions
- My invention relates broadly to radio receiving apparatus and more particularly to apparatus for the reception of continuous wave radio telegraph code signals.
- One of the objects of my invention is to provide a circuit arrangement for a continuous wave radio telegraph receiving system having means for stabilizing the tone frequency of the received signals.
- Another object of my invention is to provide an improved superheterodyne type of radio receiving circuit for the reception of continuouswave telegraph signals having means for stabilizing the tone frequency of the reproduced telegraphic signals.
- Still another object of my invention is to provide a circuit arrangement for superheterodyne type of radio receiving systems wherein the high frequency oscillator which coacts with the first detector is continuously modulated at a constant frequency adapted to be selectively impressed upon the audio frequency signal output circuit in accordance with the received telegraphic signals.
- Still another object of my invention is to provide a continuous wave superheterodyne type of radio telegraph receiving system including a high frequency oscillator arranged to coact with a first detector in combination with a source of audio frequency modulating energy which is adapted to be transferred through the intermediate frequency amplifier, second detector and audio frequency amplifier of the superheterodyne receiver in accordance with the telegraphic signals which are received for thereby determining the character of the audio frequency signaling energy which is delivered to the audio frequency signal output circuit.
- a further object of my invention is to provide a circuit arrangement for the selective reception of radio telegraph signals through a superheterodyne receiving circuit with minimum interference from static or undesired signals in which a source of audio frequency signaling energy at the receiver is rendered efiective upon a preselector circuit of an audio frequency amplification system which static high frequency oscillator which coacts with the first detector is modulated at a predetermined audio frequency rate to which the audio frequency amplification system is selectively tuned whereby the incomingtelegraphic signals effect the transfer, through the intermediate frequencyamplifier and second detector to the audio frequency amplification system, of that frequency to which the audio frequency amplification system is selectively adjusted.
- the incoming signal frequency to a frequency of a different value.
- the oscillator inasuperheterodyne receiving system be continuously modulated at. aconstantaudio frequency, this audio frequency will not pass through the intermediate frequency amplifier, second detector and 'audiofrequency amplifier unless a continuous. wave incoming signal isalso present.
- an incoming continuous wave signal When'it reaches the oscillator, besides being converted to a different frequency, also becomes modulated at the audio frequency.
- the converted andmodulated signal will then pass through the intermediate frequency amplifier, second detector andaudio frequency amplifier and the dots and dashes will be reproduced at thefrequency of the audio modulation.
- the system of my invention is rendered especially selective by reason of the. peaked characteristic of the audio frequency amplifier at a certain frequency.
- I may also employ an audio frequency amplifier having a sharp band passcharacteristic for the purpose of eliminating interference or reducing the response of the re-,
- the audio frequen cy response characteristic of the audio frequency amplifier system is selectedto correspond to the modulation and frequency ofth-e highfrequency oscillator, thereby rejecting -undesired signal fre i superheterodyne receiver circuit comprising the antenna circuit l, the radio frequency amplifier 2, the first detector 3, the oscillator 4, the intermediate frequency amplifier 5, second detector 6, audio frequency amplifier "I, and audio frequency output circuit 8 which connects to a signal indicating device, recorder or printing mechanism.
- the oscillator 4 is modulated by the source of audio voltage I which is introduced into the oscillator circuit through the coupling transformer 9.
- the coupling transformer 9 includes a primary winding H connected with the source of audio voltage I 0 and a secondary winding l2 connected in series with the input circuit of the oscillator between the biasing resistor l4 and the lower terminal of the tuned circuit 15.
- the oscillator includes the coupling coil IS in the output circuit thereof inductively related to the inductance of the tuned circuit [5 in the input circuit of the oscillator.
- the high frequency oscillations generated by oscillator 4- are impressed upon the circuit of the first detector 3 by the electro-magnetic coupling between oscillator coils l5, l6 and the tuned grid circuit of the detector 3.
- the source. of potential [8 supplies plate excitation for all of the electron tubes.
- the audio frequency amplificationsystem which has been represented for purposes of explaining my invention, has a single amplifier stage, preceded by a preselector circuit which I have designated at I9.
- the preselector circuit includes the secondary Winding audio frequency transformer 20 with a condenser 2
- the tuned circuit 19 is selectively responsive to the frequency of the modulator Hl, interfering. frequencies and static effects produce a minimum effect upon audio frequency amplification system 1.
- the tuned circuit I9 is matched to the frequency of the modulator Ill.
- the frequency of the modulator ID will not pass through the intermediate amplifier 5 or the second detector E to the transformer 20 and preselector circuit I9 unless a continuous wave incoming signal is also present.
- a continuous wave incoming signal reaches the oscillator, the beat or intermediate frequency thereby produced isv impressed upon the intermediate frequency amplifier 5 and at the same time the modulation to say, thehigh frequency path from the end of tuned circuit l5 to the'cathode of tube 4 is closed through condenser 22 while allowing audio frequency oscillations to be impressed from source I0 upon the input circuit of the'oscillator '4.
- a continuous wave radio telegraph receiving system comprising a superheterodyne receiving circuit including a first detector, a high frequency oscillator connected therewith, an intermediate frequency amplifier connected with said first detector, a second detector connected with said intermediate frequency amplifier, a preselector circuit connected with the output of said second detector, an audio frequency amplifier system connected with said preselector circuit and a source of audio frequency oscillation connected with said high frequency oscillator, said preselector circuit being tuned to select the frequency of said source of audio frequency oscillation.
- a continuous wave radio telegraph receiving system comprising a superheterodyne receiving circuit including-a first detector, a high frequency oscillator connected therewith, an intermediate frequency amplifier connected with said first detector, a second detector connected with said intermediate frequency amplifier, a preselector circuit comprising a tunable condenser and a winding of an audio frequency transformer connected with the output of said second detector, an audio frequency amplifier system connected with said preselector circuit and a source oflaudio frequency oscillation connected'with' said high frequency oscillator for continuously modulating the oscillations impressed on said first detector at an audio rate, the frequency adjustment of said preselector circuit being matched to correspond to the frequency of said source of audio frequency oscillations.
- A- continuous wave radio telegraph receiving system comprising a superheterodyne receiving circuit including a first detector, ahigh frequency oscillator connected therewith, an intermediate frequency amplifier connected with said first detector, a second detector connected with said intermediate frequency amplifier, a preselector circuit connected with the output of said second detector, an audio frequency am-- plifier system connected with said preselector circuit, a source of audio frequency oscillation connected between the grid and cathode of said high frequency oscillator for continuously modulating the oscillations-impressed on said first detector at an audio rate, and a radio' frequency by-pass condenser also connected to saidgrid and cathode, said preselector circuit being tuned to select the frequency of said source of audio frequency oscillation.
- a continuous wave radio telegraph receiving system comprising a superheterodyne receiving circuit ,including- .afirst detector, 2. high frequency oscillator connected therewith, an intermediate frequency amplifier connected with said first'detector, a second detector connected with .said intermediate frequency amplifier, a preselector circuit comprising a variable condenser and an inductance connected with the output of said second detector, an audio frequency amplifier system connected with said preselector cirouit.. a.
- source of plate supply for said high frequency oscillations said source supplying energy for the plate circuits of said first and second detectors and said intermediate and audio frequency amplifiers, a source of audio frequency oscillation connected between the grid and cathode of said high frequency oscillator for continuously modulating the oscillations impressed on said first detector at an audio rate, and means for bypassing the high frequency oscillations generated by said oscillator around said source of audio frequency oscillations, said condenser of said preselector circuit being capable of adjusting said circuit to the frequency of said audio frequency source.
- a continuous wave radio telegraph receiving system comprising a superheterodyne receiving circuit including a first detector, a high frequency oscillator having a tuned circuit connected at one end to the grid of the oscillator, a connection between the other end of said tuned circuit and the cathode, a transformer having the secondary winding thereof disposed in said connection, a source of audio frequency oscillations connected with the primary winding of said transformer, an intermediate frequency amplifier connected with said first detector, a second detector connected with said intermediate frequency amplifier, a common source of plate supply for all stages of said receiving system, a preselector circuit connected with said second detector, and an audio frequency amplification system connected with said preselector circuit, and means for adjusting said preselector circuit to the frequency of said audio frequency source.
- a continuous wave radio telegraph receiving system comprising a superheterodyne receiving circuit including a first detector, a high frequency oscillator having a tuned circuit connected at one end to the grid of the oscillator, a connection between the other end of said tuned circuit and the cathode, a transformer having the secondary winding thereof disposed in said connection, a source of audio frequency oscillations connected with the primary winding of said transformer, an intermediate frequency amplifier connected with said first detector, a second detector connected with said intermediate frequency amplifier, a preselector circuit connected with said second detector, an audio frequency amplification system connected with said preselector circuit, means for adjusting said preselector circuit to the frequency of said audio frequency source, and means connected across the secondary winding of said transformer forming a closed path for the high frequency oscillations generated by said oscillator around said source of audio frequency oscillations.
- a continuous wave radio telegraph receiving system comprising a superheterodyne receiving circuit including a first detector, a high frequency oscillator having a tuned circuit connected at one end to the grid of the oscillator, a connection between the other end of said tuned circuit and the cathode, a transformer having the secondary winding thereof disposed in said connection, a source of audio frequency oscillations connected with the primary winding of said transformer, an intermediate frequency amplifier connected with said first detector, a second detector connected with said intermediate frequency amplifier, a preselector circuit connected with said second detector, an audio frequency amplification system connected with said 'preselector circuit, means for adjusting said preselector circuit to the frequency of said audio frequency source, and a condenser connected across the secondary winding of said transformer for forming a closed path for the high frequency oscillations generated by said oscillator around said source of audio frequency oscillations.
- a superheterodyne high-frequency signal receiving system in combination, a first detector, a local oscillator coupled with the first detector for supplying an oscillation to beat with an incoming continuous wave signal to produce an intermediate frequency wave, an auxiliary os-' cillator adapted to modulate said local oscillator at a constant audio frequency, said intermediate frequency wave being thereby likewise modulated and having besides the character of the incoming continuous wave signal, an intermediate frequency amplifier coupled with said first detector, a second detector, and an audio frequency amplifier peaked at the said audio frequency.
- a superheterodyne high-frequency continuous wave signal receiving system in combination, a first detector, a local oscillator, an intermediate frequency amplifier, a second detector, means for modulating the current in said intermediate frequency amplifier at a constant audible frequency and in the character of the received signal, said audible frequency modulation being detected in said second detector in the character of the received signal, and an audio frequency filter and a peaked audio frequency amplifier for selectively amplifying said modulation.
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Superheterodyne Receivers (AREA)
Description
Sept. 27, 1938. P. D. LOWELL 2,131,109
RADIO TELEGRAPH RECEIVING SYSTEM I Filed July 25, 1953 Patented Sept. 27, 1938 UNITED STATES RADIO TELEGRAPH RECEIVING SYSTEM Percival D. Lowell, Chevy Chase, Md., assignor to Radio Corporation of America, New York, N. Y., a corporation of Delaware Application July 25, 1933, Serial No. 682,132
9 Claims.
My invention relates broadly to radio receiving apparatus and more particularly to apparatus for the reception of continuous wave radio telegraph code signals.
One of the objects of my invention is to provide a circuit arrangement for a continuous wave radio telegraph receiving system having means for stabilizing the tone frequency of the received signals.
Another object of my invention is to provide an improved superheterodyne type of radio receiving circuit for the reception of continuouswave telegraph signals having means for stabilizing the tone frequency of the reproduced telegraphic signals.
Still another object of my invention is to provide a circuit arrangement for superheterodyne type of radio receiving systems wherein the high frequency oscillator which coacts with the first detector is continuously modulated at a constant frequency adapted to be selectively impressed upon the audio frequency signal output circuit in accordance with the received telegraphic signals.
Still another object of my invention is to provide a continuous wave superheterodyne type of radio telegraph receiving system including a high frequency oscillator arranged to coact with a first detector in combination with a source of audio frequency modulating energy which is adapted to be transferred through the intermediate frequency amplifier, second detector and audio frequency amplifier of the superheterodyne receiver in accordance with the telegraphic signals which are received for thereby determining the character of the audio frequency signaling energy which is delivered to the audio frequency signal output circuit.
7 A further object of my invention is to provide a circuit arrangement for the selective reception of radio telegraph signals through a superheterodyne receiving circuit with minimum interference from static or undesired signals in which a source of audio frequency signaling energy at the receiver is rendered efiective upon a preselector circuit of an audio frequency amplification system which static high frequency oscillator which coacts with the first detector is modulated at a predetermined audio frequency rate to which the audio frequency amplification system is selectively tuned whereby the incomingtelegraphic signals effect the transfer, through the intermediate frequencyamplifier and second detector to the audio frequency amplification system, of that frequency to which the audio frequency amplification system is selectively adjusted. I I
Other and further objects of my invention reside in the selective continuous wave. radio telegraph signal receiving system as set forth more fully in the specification hereinafterfollowing by reference .to the accompanying drawing which Vention. V
.,In. thelcircuits now commonly used in radio telegraphy it is customary to employ either an oscillating detector or a separate oscillator for the ,purpose. of generatingoscillati'ons to beat with the incoming signal waves, thereby rendering the:
incoming code signals audible to, the ear or useful in operating arecorder'or printer; It is the purpose of my invention to provide a more stable,
simpler and-more easily. adjusted method of rendering the continuous wave signals audible than that obtainable in'the usual beat frequency.
'the incoming signal frequency to a frequency of a different value. I havefound that if the oscillator inasuperheterodyne receiving system be continuously modulated at. aconstantaudio frequency, this audio frequency will not pass through the intermediate frequency amplifier, second detector and 'audiofrequency amplifier unless a continuous. wave incoming signal isalso present. In otherwords, an incoming continuous wave signal When'it reaches the oscillator, besides being converted to a different frequency, also becomes modulated at the audio frequency. The converted andmodulated signal will then pass through the intermediate frequency amplifier, second detector andaudio frequency amplifier and the dots and dashes will be reproduced at thefrequency of the audio modulation. The system of my invention is rendered especially selective by reason of the. peaked characteristic of the audio frequency amplifier at a certain frequency. I may also employ an audio frequency amplifier having a sharp band passcharacteristic for the purpose of eliminating interference or reducing the response of the re-,
ceiver to static disturbances. The audio frequen cy response characteristic of the audio frequency amplifier system is selectedto correspond to the modulation and frequency ofth-e highfrequency oscillator, thereby rejecting -undesired signal fre i superheterodyne receiver circuit comprising the antenna circuit l, the radio frequency amplifier 2, the first detector 3, the oscillator 4, the intermediate frequency amplifier 5, second detector 6, audio frequency amplifier "I, and audio frequency output circuit 8 which connects to a signal indicating device, recorder or printing mechanism. The oscillator 4 is modulated by the source of audio voltage I which is introduced into the oscillator circuit through the coupling transformer 9. The coupling transformer 9 includes a primary winding H connected with the source of audio voltage I 0 and a secondary winding l2 connected in series with the input circuit of the oscillator between the biasing resistor l4 and the lower terminal of the tuned circuit 15. The oscillator includes the coupling coil IS in the output circuit thereof inductively related to the inductance of the tuned circuit [5 in the input circuit of the oscillator. The high frequency oscillations generated by oscillator 4- are impressed upon the circuit of the first detector 3 by the electro-magnetic coupling between oscillator coils l5, l6 and the tuned grid circuit of the detector 3. The source. of potential [8 supplies plate excitation for all of the electron tubes. I have illustrated the indirectly heated type of electron tube employed in the oscillator and throughout the several stages of the receiver. The audio frequency amplificationsystem which has been represented for purposes of explaining my invention, has a single amplifier stage, preceded by a preselector circuit which I have designated at I9. The preselector circuit includes the secondary Winding audio frequency transformer 20 with a condenser 2| connected in shunt I thereto and adjusted. to the audio frequency produced by the source of audio voltage Ill. Inasmuchas the tuned circuit 19 is selectively responsive to the frequency of the modulator Hl, interfering. frequencies and static effects produce a minimum effect upon audio frequency amplification system 1. The tuned circuit I9 is matched to the frequency of the modulator Ill. The frequency of the modulator ID will not pass through the intermediate amplifier 5 or the second detector E to the transformer 20 and preselector circuit I9 unless a continuous wave incoming signal is also present. When a continuous wave incoming signal reaches the oscillator, the beat or intermediate frequency thereby produced isv impressed upon the intermediate frequency amplifier 5 and at the same time the modulation to say, thehigh frequency path from the end of tuned circuit l5 to the'cathode of tube 4 is closed through condenser 22 while allowing audio frequency oscillations to be impressed from source I0 upon the input circuit of the'oscillator '4.
I have found the continuous wave: receiving 75.:system of my invention highly practical in its:-
operation. I have used the circuit in the operation of automatic printers by radio with highly successful results over substantial distances. While I have described my invention in one of its preferred embodiments, I desire that it be understood that modifications may be made and that no limitations upon my invention are intended other than are imposed by the scope of the appended claims.
What I claim as new and desire to secure by Letters Patent of the United States is as follows:
1. A continuous wave radio telegraph receiving system comprising a superheterodyne receiving circuit including a first detector, a high frequency oscillator connected therewith, an intermediate frequency amplifier connected with said first detector, a second detector connected with said intermediate frequency amplifier, a preselector circuit connected with the output of said second detector, an audio frequency amplifier system connected with said preselector circuit and a source of audio frequency oscillation connected with said high frequency oscillator, said preselector circuit being tuned to select the frequency of said source of audio frequency oscillation.
. 2. A continuous wave radio telegraph receiving system comprising a superheterodyne receiving circuit including-a first detector, a high frequency oscillator connected therewith, an intermediate frequency amplifier connected with said first detector, a second detector connected with said intermediate frequency amplifier, a preselector circuit comprising a tunable condenser and a winding of an audio frequency transformer connected with the output of said second detector, an audio frequency amplifier system connected with said preselector circuit and a source oflaudio frequency oscillation connected'with' said high frequency oscillator for continuously modulating the oscillations impressed on said first detector at an audio rate, the frequency adjustment of said preselector circuit being matched to correspond to the frequency of said source of audio frequency oscillations.
3. A- continuous wave radio telegraph receiving system comprising a superheterodyne receiving circuit including a first detector, ahigh frequency oscillator connected therewith, an intermediate frequency amplifier connected with said first detector, a second detector connected with said intermediate frequency amplifier, a preselector circuit connected with the output of said second detector, an audio frequency am-- plifier system connected with said preselector circuit, a source of audio frequency oscillation connected between the grid and cathode of said high frequency oscillator for continuously modulating the oscillations-impressed on said first detector at an audio rate, and a radio' frequency by-pass condenser also connected to saidgrid and cathode, said preselector circuit being tuned to select the frequency of said source of audio frequency oscillation.
4. A continuous wave radio telegraph receiving system comprising a superheterodyne receiving circuit ,including- .afirst detector, 2. high frequency oscillator connected therewith, an intermediate frequency amplifier connected with said first'detector, a second detector connected with .said intermediate frequency amplifier, a preselector circuit comprising a variable condenser and an inductance connected with the output of said second detector, an audio frequency amplifier system connected with said preselector cirouit.. a. source of plate supply for said high frequency oscillations, said source supplying energy for the plate circuits of said first and second detectors and said intermediate and audio frequency amplifiers, a source of audio frequency oscillation connected between the grid and cathode of said high frequency oscillator for continuously modulating the oscillations impressed on said first detector at an audio rate, and means for bypassing the high frequency oscillations generated by said oscillator around said source of audio frequency oscillations, said condenser of said preselector circuit being capable of adjusting said circuit to the frequency of said audio frequency source.
5. A continuous wave radio telegraph receiving system comprising a superheterodyne receiving circuit including a first detector, a high frequency oscillator having a tuned circuit connected at one end to the grid of the oscillator, a connection between the other end of said tuned circuit and the cathode, a transformer having the secondary winding thereof disposed in said connection, a source of audio frequency oscillations connected with the primary winding of said transformer, an intermediate frequency amplifier connected with said first detector, a second detector connected with said intermediate frequency amplifier, a common source of plate supply for all stages of said receiving system, a preselector circuit connected with said second detector, and an audio frequency amplification system connected with said preselector circuit, and means for adjusting said preselector circuit to the frequency of said audio frequency source.
6. A continuous wave radio telegraph receiving system comprising a superheterodyne receiving circuit including a first detector, a high frequency oscillator having a tuned circuit connected at one end to the grid of the oscillator, a connection between the other end of said tuned circuit and the cathode, a transformer having the secondary winding thereof disposed in said connection, a source of audio frequency oscillations connected with the primary winding of said transformer, an intermediate frequency amplifier connected with said first detector, a second detector connected with said intermediate frequency amplifier, a preselector circuit connected with said second detector, an audio frequency amplification system connected with said preselector circuit, means for adjusting said preselector circuit to the frequency of said audio frequency source, and means connected across the secondary winding of said transformer forming a closed path for the high frequency oscillations generated by said oscillator around said source of audio frequency oscillations.
7. A continuous wave radio telegraph receiving system comprising a superheterodyne receiving circuit including a first detector, a high frequency oscillator having a tuned circuit connected at one end to the grid of the oscillator, a connection between the other end of said tuned circuit and the cathode, a transformer having the secondary winding thereof disposed in said connection, a source of audio frequency oscillations connected with the primary winding of said transformer, an intermediate frequency amplifier connected with said first detector, a second detector connected with said intermediate frequency amplifier, a preselector circuit connected with said second detector, an audio frequency amplification system connected with said 'preselector circuit, means for adjusting said preselector circuit to the frequency of said audio frequency source, and a condenser connected across the secondary winding of said transformer for forming a closed path for the high frequency oscillations generated by said oscillator around said source of audio frequency oscillations.
8. In a superheterodyne high-frequency signal receiving system, in combination, a first detector, a local oscillator coupled with the first detector for supplying an oscillation to beat with an incoming continuous wave signal to produce an intermediate frequency wave, an auxiliary os-' cillator adapted to modulate said local oscillator at a constant audio frequency, said intermediate frequency wave being thereby likewise modulated and having besides the character of the incoming continuous wave signal, an intermediate frequency amplifier coupled with said first detector, a second detector, and an audio frequency amplifier peaked at the said audio frequency.
9. In a superheterodyne high-frequency continuous wave signal receiving system, in combination, a first detector, a local oscillator, an intermediate frequency amplifier, a second detector, means for modulating the current in said intermediate frequency amplifier at a constant audible frequency and in the character of the received signal, said audible frequency modulation being detected in said second detector in the character of the received signal, and an audio frequency filter and a peaked audio frequency amplifier for selectively amplifying said modulation.
PERCIVAL D. LOWELL.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US682132A US2131109A (en) | 1933-07-25 | 1933-07-25 | Radio telegraph receiving system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US682132A US2131109A (en) | 1933-07-25 | 1933-07-25 | Radio telegraph receiving system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2131109A true US2131109A (en) | 1938-09-27 |
Family
ID=24738352
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US682132A Expired - Lifetime US2131109A (en) | 1933-07-25 | 1933-07-25 | Radio telegraph receiving system |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2131109A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2450913A (en) * | 1945-04-04 | 1948-10-12 | Peterson Glen | Radiotelegraphy superregenerative receiver |
| DE907665C (en) * | 1941-04-10 | 1954-03-29 | Julius Pintsch K G | Overlay receiver for or with search reception |
| US2699495A (en) * | 1950-10-03 | 1955-01-11 | Motorola Inc | Automatic switchover system for radio relay |
| US2901613A (en) * | 1957-08-05 | 1959-08-25 | Hubert H Patterson | Detector for modulated and unmodulated signals |
| US2920190A (en) * | 1955-10-17 | 1960-01-05 | Arf Products | Radio receiver having means to wobble local oscillator during tuning |
| US2983814A (en) * | 1956-02-01 | 1961-05-09 | Raytheon Co | Signal receivers |
| US3018369A (en) * | 1958-03-12 | 1962-01-23 | Rca Corp | Transistorized direction finder receiver having a local audio signal modulated on the mixer |
-
1933
- 1933-07-25 US US682132A patent/US2131109A/en not_active Expired - Lifetime
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE907665C (en) * | 1941-04-10 | 1954-03-29 | Julius Pintsch K G | Overlay receiver for or with search reception |
| US2450913A (en) * | 1945-04-04 | 1948-10-12 | Peterson Glen | Radiotelegraphy superregenerative receiver |
| US2699495A (en) * | 1950-10-03 | 1955-01-11 | Motorola Inc | Automatic switchover system for radio relay |
| US2920190A (en) * | 1955-10-17 | 1960-01-05 | Arf Products | Radio receiver having means to wobble local oscillator during tuning |
| US2983814A (en) * | 1956-02-01 | 1961-05-09 | Raytheon Co | Signal receivers |
| US2901613A (en) * | 1957-08-05 | 1959-08-25 | Hubert H Patterson | Detector for modulated and unmodulated signals |
| US3018369A (en) * | 1958-03-12 | 1962-01-23 | Rca Corp | Transistorized direction finder receiver having a local audio signal modulated on the mixer |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US2131109A (en) | Radio telegraph receiving system | |
| US1993395A (en) | Signal generator | |
| US1861462A (en) | Radio station | |
| US2024138A (en) | Radio signaling system | |
| US1734038A (en) | Electrical transmission of energy | |
| US2519256A (en) | High fidelity modulator | |
| US2125953A (en) | Receiver of telephonic or telegraphic signals | |
| US1819299A (en) | Tuning system | |
| US1762945A (en) | Radio receiving system | |
| US2026759A (en) | Superheterodyne receiver | |
| US2066940A (en) | Radio receiving system | |
| US1847190A (en) | Electric wave signaling system | |
| USRE19765E (en) | Badioreceiveb | |
| US2279095A (en) | Superregenerative receiver | |
| US1675848A (en) | Transmission regulation | |
| US2123221A (en) | Radio circuit for channel reception | |
| US2023222A (en) | Ringing circuit for radio | |
| US1872364A (en) | Radiotransmitting system | |
| US1654976A (en) | Vacuum-tube circuits | |
| US2154723A (en) | Short wave radio amplifying and receiving system | |
| US1885299A (en) | Monitoring system | |
| US1744836A (en) | Carrier-amplitude control in radio systems | |
| US1868614A (en) | Signaling system | |
| US1847142A (en) | Means and method for signaling by electric waves | |
| US2039923A (en) | Superheterodyne receiver |