CN204795565U - Short distance 3. 5MHz radio direction finding machine - Google Patents
Short distance 3. 5MHz radio direction finding machine Download PDFInfo
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- CN204795565U CN204795565U CN201520424880.5U CN201520424880U CN204795565U CN 204795565 U CN204795565 U CN 204795565U CN 201520424880 U CN201520424880 U CN 201520424880U CN 204795565 U CN204795565 U CN 204795565U
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Abstract
The utility model relates to a short distance 3.5MHz radio direction finding machine, the glass controller module comprises a housing and a control circuit disposed in the housing, control circuit includes the direction -finder antenna, the high -frequency amplification unit, adjustable signal generator based on heter rodyne action, difference frequency detection unit and audio power amplifier unit, the input of direction -finder antenna and high -frequency amplification unit links to each other, the output of high -frequency amplification unit and the output of adjustable signal generator based on heter rodyne action are continuous with the input of difference frequency detection unit respectively, the output of difference frequency detection unit and the input of audio power amplifier unit link to each other, the output and the earphone interface of audio power amplifier unit link to each other. The utility model discloses only with an adjustable signal generator based on heter rodyne action, poor direct low frequency signals plays channel selection and beat effect simultaneously, has left out intermediate -frequency switching and treatment circuit, and the circuit is simple, uses in a flexible way, and radio reception can the reinforce, is fit for match use under special environment such as mountain region, and application range extensively satisfies the needs that radio direction finding moved under the various environment.
Description
Technical field
The utility model relates to a kind of channels watcher, particularly relates to a kind of short distance 3.5MHz channels watcher.
Background technology
Direction-finding station campaign grows up on the basis that radio amateur extensively carries out amateur communication.Direction-finding station contest is very interesting, just as playing the game of hide and seek, sportsman's audiometry busily, to run, and all over the mountains and plains goes to search hidden radio station one by one.Direction-finding station contest is very mysterious again, maintain secrecy in contest region, station location is maintained secrecy, sportsman thinks independently and moves in contest process, can not get the guidance of coach, also mustn't accept anyone any help and prompting, only have channels watcher to be athletic loyal partner, player hand takes channels watcher, wear the earphone be attached thereto and search the hidden one by one radio station that contest organizer sets in advance.
Wherein universal is 80 VHF band short-range radio radio direction findings the most widely.80 current VHF band short-range radio direction-finder sets, general employing superhet direction-finder set, it has two oscillators: one is this machine oscillator, produce the high-frequency oscillation signal of 465KHz more high or low than external Received signal strength, after high discharge signal mixing, obtain the intermediate-freuqncy signal of a 465KHz, then carry out intermediate frequency process; Another is signal generator based on heter rodyne action, produces the oscillator signal of 1KHz more high or low than 465KHz intermediate-freuqncy signal, with in put and output signal difference and go out the low frequency signal of 1KHz.This channels watcher not only circuit structure is complicated, and cost is higher, and radio reception capability is more limited.As certain match in 2013, because competition area are located at mountain region, and air line distance reaches more than 350 meters between radio station, because channels watcher receiving ability used is inadequate, just there occurs playing area and search the phenomenon not detecting radio station, many sportsmen, because can't hear radio station and abandon match, also have componental movement person to survey on a large amount of physical efficiency to put into and cross over mountain after mountain by radio station to search, have impact on competition effect, also bring certain danger.
Summary of the invention
It is complicated that the utility model mainly solves original channels watcher circuit structure, and radio reception capability is more limited, is not suitable for match under the particular surroundingss such as mountain region and uses, the more restricted technical problem of the scope of application; There is provided a kind of short distance 3.5MHz channels watcher, its circuit is simple, and radio reception capability is comparatively strong, and under being adapted at the particular surroundingss such as mountain region, match uses, and the scope of application is wide, meets the needs of direction-finding station campaign under various environment.
Above-mentioned technical problem of the present utility model is mainly solved by following technical proposals: the utility model comprises housing and is located at the control circuit in housing, control circuit comprises direction-finder antenna, high-frequency amplifying unit, adjustable signal generator based on heter rodyne action, difference frequency detection unit and audio amplification unit, direction-finder antenna is connected with the input of high-frequency amplifying unit, the output of high-frequency amplifying unit and the output of adjustable signal generator based on heter rodyne action are connected with the input of difference frequency detection unit respectively, the output of difference frequency detection unit is connected with the input of audio amplification unit, the output of audio amplification unit is connected with earphone interface.After direction-finder antenna receives the able one signal of 3.5 ~ 3.6MHz that radio station sends, deliver to high-frequency amplifying unit to amplify, difference frequency detection unit is added to together with the second harmonic of the oscillator signal of 1.75 ~ 1.8MHz that the signal after amplification and adjustable signal generator based on heter rodyne action produce, the frequency of adjustment signal generator based on heter rodyne action, it is made to produce the signal of 1KHz more high or low than Received signal strength, the output signal of this signal and high-frequency amplifying unit carries out difference frequency detection, obtain the low frequency signal of 1KHz, and then deliver to audio amplification unit and amplify, earphone is given finally by earphone interface, sportsman just can the uppick radio station telegraphic signal that sends.The utility model only uses an oscillator, i.e. adjustable signal generator based on heter rodyne action, directly poor go out low frequency signal, play channel selection and beat effect simultaneously, do not have local oscillator level and in put level, eliminate intermediate frequency conversion and treatment circuit, circuit is simple, uses flexibly, radio reception capability is stronger, be adapted at match under the particular surroundingss such as mountain region to use, the scope of application is wide, meets the needs of direction-finding station campaign under various environment.
As preferably, described audio amplification unit comprises audio frequency pre-amplifier unit and Audio power amplifier unit, the input of audio frequency pre-amplifier unit is connected with the output of described difference frequency detection unit, the output of audio frequency pre-amplifier unit is connected with the input of described Audio power amplifier unit, and the output of Audio power amplifier unit is connected with described earphone interface.When direction-finder set is away from radio station, the output signal of difference frequency detection unit can be very weak, therefore first carries out low frequency amplification by audio frequency pre-amplifier unit, then carry out power amplification by Audio power amplifier unit, effective enhancing signal, guarantees that the telegraphic signal that sportsman hears from earphone is more clear.
As preferably, described adjustable signal generator based on heter rodyne action comprises beat oscillator coil B2, triode T3, variable capacitance diode D2, adjustable resistance RP3 and voltage-stabiliser tube D3, the collector electrode of triode T3 and the negative pole of voltage-stabiliser tube D3, a stiff end of adjustable resistance RP3 is connected and connects voltage B and holds, another stiff end of adjustable resistance RP3 meets voltage V2 through resistance R14 and holds, the positive pole of voltage-stabiliser tube D3 also meets voltage V2 and holds, the emitter of triode T3 meets voltage V2 through the parallel circuits of resistance R12 and electric capacity C18 and holds, electric capacity C17 and voltage-stabiliser tube D3 is in parallel, the movable end of adjustable resistance RP3 is connected with one end of electric capacity C20 and resistance R13, the other end of electric capacity C20 is connected with the negative pole of voltage-stabiliser tube D3, the other end of resistance R13 is connected with the negative pole of variable capacitance diode D2, the positive pole of variable capacitance diode D2 meets voltage V2 and holds, one end of resistance R10 is connected with the collector electrode of triode T3, one end of electric capacity C16 is connected with the emitter of triode T3, the other end of resistance R10 and electric capacity C16 is all connected with one end of resistance R11, another termination voltage V2 of resistance R11 holds, the base stage of triode T3 is connected with one end of the primary coil of beat oscillator coil B2, the other end of the primary coil of beat oscillator coil B2 had not only met voltage V2 through electric capacity C14 and has held but also be connected with the negative pole of variable capacitance diode D2 through electric capacity C15, one end of the secondary wire coil of beat oscillator coil B2 is connected with the input of described difference frequency detection unit, another termination voltage V2 of the secondary wire coil of beat oscillator coil B2 holds.The adjustable signal generator based on heter rodyne action of the technical program is tandem type Colpitts oscillation circuit.Adopt electric tuning mode, by regulating adjustable resistance RP3, the bias voltage that change is added on variable capacitance diode D2 to change the capacitance at variable capacitance diode D2 two ends, thus changes frequency of oscillation, reaches the object adjusting platform.Adjustable resistance RP3, resistance R13 and resistance R14 form the biasing circuit of variable capacitance diode D2.For obtaining wider frequency range, optional electricity capacity changes variable capacitance diode greatly, also can change the resistance of resistance R13, resistance R14.Electric capacity C14, electric capacity C15 are loop resonance electric capacity, and for improving the frequency stability of circuit, electric capacity C14, electric capacity C15 can select the electric capacity that temperature coefficient is less.Voltage-stabiliser tube D3 plays the effect of stabilized oscillator operating voltage.
As preferably, described difference frequency detection unit comprises detection tube D1, the filter circuit be made up of electric capacity C5, electric capacity C6 and resistance R5 and detection load resistance R6, the positive pole of detection tube D1 is connected with the output of described high-frequency amplifying unit, the negative pole of detection tube D1 had not only been connected through electric capacity C5 ground connection but also with one end of resistance R5, the other end of resistance R5 had not only been connected with the input of described audio amplification unit but also through electric capacity C6 ground connection, detection load resistance R6 and electric capacity C6 is in parallel.Detection tube D1 is a nonlinear device with unilateral conduction, utilizes it that the signal of two different frequencies can be made to produce many new frequency contents.Such as, except original two frequencies, also has difference of two frequency sums, two frequencies etc.A frequency content is only had to be the difference (about 1KHz) of second harmonic of extraneous signal frequency after high-frequency amplifying unit amplifies and signal generator based on heter rodyne action frequency.Electric capacity C5, electric capacity C6 and resistance R5 form RC type filter circuit, and RC type filter circuit is used for the radio-frequency component after filtering detection, to obtain low-frequency voltage on detection load resistance R6.
As preferably, described high-frequency amplifying unit comprises triode T1, high unwrapping wire circle B1 and adjustable resistance RP1, the base stage of triode T1, one tunnel is connected with the output of described direction-finder antenna through electric capacity C2, another road is through resistance R2 ground connection, a road is also had to be connected with the movable end of adjustable resistance RP1 through resistance R1, a stiff end ground connection of adjustable resistance RP1, another stiff end of adjustable resistance RP1 is connected with voltage V1 end, the emitter of triode T1 is through the parallel circuits ground connection of electric capacity C4 and resistance R3, the collector electrode of triode T1 is connected with one end of the primary coil of high unwrapping wire circle B1, the parallel connection of primary windings of electric capacity C3 and high unwrapping wire circle B1, the middle tap of the primary coil of high unwrapping wire circle B1 to be not only connected but also through electric capacity C19 ground connection through resistance R4 and voltage V1 end, the secondary coil of high unwrapping wire circle B1 is connected with the input of described difference frequency detection unit.Resistance R1 ~ resistance R4 is biasing resistor, and electric capacity C2 is coupling capacitance, and electric capacity C3 is resonant capacitance, and electric capacity C4 is shunt capacitance.Adjust the magnetic core of high unwrapping wire circle B1, resonance, in 3.57MHz, can carry out staggered tuning with the resonance frequency 3.53MHz of direction-finder antenna, and make whole High frequency amplification curve all comparatively mild in the receive frequency range of 3.5 ~ 3.6MHz, namely high amplification gain is more even.For making channels watcher high level of putting when the strong signal in close-table district not occur choking phenomenon, still can maintain and amplify and keep good directivity normally, can control highly to put level work point by adjustment adjustable resistance RP1, reach the object controlling high amplification gain.The method not only eliminates attenuator switch, and can obtain the gain control range of non-constant width.
As preferably, described audio frequency pre-amplifier unit comprises triode T2, described Audio power amplifier unit comprises adjustable resistance RP2 and amplifier U, the base stage of triode T2 had not only been connected through electric capacity C8 with the output of described difference frequency detection unit but also had been connected with the collector electrode of triode T2 through resistance R8, the grounded emitter of triode T2, the collector electrode of triode T2 had not only been connected through resistance R9 with voltage V1 end but also had been connected with the positive pole of electrochemical capacitor C10, the negative pole of electrochemical capacitor C10 had not only been connected through electric capacity C11 ground connection but also with a stiff end of adjustable resistance RP2, another stiff end ground connection of adjustable resistance RP2, the movable end of adjustable resistance RP2 is connected with the inverting input of amplifier U, the in-phase input end ground connection of amplifier U, voltage V1 end is connected with one end of resistance R7, the other end of resistance R7 had not only been connected through electrochemical capacitor C9 ground connection but also through the positive pole of K switch with battery BT, the output of amplifier U is connected with the positive pole of electrochemical capacitor C13, the negative pole of electrochemical capacitor C13 is connected with the positive pole of earphone socket CK, the minus earth of earphone socket CK, amplifier U is also connected with feedback capacity C12, adjustable resistance RP2 and adjustable resistance RP1 adopts the coaxial duplex potentiometer controlled.Triode T2, resistance R8, resistance R9 and electric capacity C8, electrochemical capacitor C10 form emitting stage amplifier altogether, and wherein resistance R8, resistance R9 are negative voltage feedback biasing circuit, and electric capacity C8, electrochemical capacitor C10 are coupling capacitor.When channels watcher is away from radio station, the audio signal that difference frequency detection unit exports will be very weak, and the technical program is first once amplified it with low frequency triode T2, then carries out common emitting stage amplification, strengthen signal, guarantee that sportsman can clearly recognize.Signal after audio frequency enlarge leadingly is bonded to amplifier U through electrochemical capacitor C10 lotus root and carries out power amplification.When feedback capacity C12 is 10 μ F, the voltage gain of amplifier U can reach 100 times.Regulate adjustable resistance RP2, the volume of the audio signal of output can be changed.Electric capacity C11 is high-frequency bypass capacitor, makes the higher partial short circuit of audio signal medium frequency enter ground and not be exaggerated, to weaken " neighing " background noise ear-piercing in earphone.Electrochemical capacitor C13 is output coupling capacitor, and the adjustable resistance RP1 in adjustable resistance RP2 and high-frequency amplifying unit coaxially controls.
As preferably, described direction-finder antenna comprises upright antenna, single-direction and dual-direction change over switch S and the magnetic antenna L1 be coupled mutually and magnetic antenna L2, upright antenna is connected with the public pin of single-direction and dual-direction change over switch S, the haptic element of single-direction and dual-direction change over switch S is through the series circuit ground connection of phase modulation resistance R15 and tuning capacitance C1, magnetic antenna L1 and tuning capacitance C1 is in parallel, another haptic element of single-direction and dual-direction change over switch S and the equal ground connection in one end of magnetic antenna L2, the other end of magnetic antenna L2 is connected with the input of described high-frequency amplifying unit.Adjustment tuning capacitance C1, makes antenna loop resonance in 3.53MHz.When needing to carry out surveying large sound face, control single-direction and dual-direction change over switch S, upright antenna and magnetic antenna L1 are connected, the signal that upright antenna receives is coupled to magnetic antenna L2 by magnetic antenna L1, then flows to high-frequency amplifying unit.During the large sound face of accident, do not need access magnetic antenna L1, control single-direction and dual-direction change over switch S, make upright antenna directly and magnetic antenna L2 connect, the signal of upright antenna reception flows to high-frequency amplifying unit again by magnetic antenna L2.Use flexibly.
As preferably, described housing is cuboid, the end face of housing is located at by described upright antenna, the left side of housing, right side respectively has one to protrude left, the cylinder protective cover protruded to the right, two protective covers are near the top of housing, described magnetic antenna L1 and magnetic antenna L2 lays respectively at left side protective cover, in the protective cover of right side, the left side of housing is provided with adjusts platform knob and volume adjustment knob, described single-direction and dual-direction change over switch S adopts push switch, push switch is located at the right side of housing, described earphone interface adopts the earphone interface with mains switch, earphone interface is located at the right side of housing.Adjustable resistance RP1 in high-frequency amplifying unit and the adjustable resistance RP2 in Audio power amplifier unit coaxially controls, and forms volume adjustment knob; Adjustable resistance RP3 in adjustable signal generator based on heter rodyne action, forms and adjusts platform knob.Protective cover plays a protective role to magnetic antenna L1 and magnetic antenna L2, only can be damaged to protective cover, can not be damaged to magnetic antenna because of transport, vibrations or when colliding with because of carelessness.
The beneficial effects of the utility model are: only with an adjustable signal generator based on heter rodyne action, directly poor go out low frequency signal, play channel selection and beat effect simultaneously, eliminate intermediate frequency conversion and treatment circuit, circuit is simple, uses flexibly, radio reception capability is strong, be adapted at match under the particular surroundingss such as mountain region to use, the scope of application is wide, meets the needs of direction-finding station campaign under various environment.
Accompanying drawing explanation
Fig. 1 is the main TV structure schematic diagram of one of the present utility model.
Fig. 2 is a kind of circuit theory syndeton block diagram of the present utility model.
Fig. 3 is a kind of circuit theory diagrams of the present utility model.
1. housings, 2. direction-finder antenna, 3. high-frequency amplifying unit in figure; 4. adjustable signal generator based on heter rodyne action, 5. difference frequency detection unit, 6. audio amplification unit; 7. earphone interface; 8. audio frequency pre-amplifier unit, 9. Audio power amplifier unit, 10. protective cover; 11. adjust platform knob; 12. volume adjustment knobs, 13. push switch, 21. upright antennas.
Embodiment
Below by embodiment, and by reference to the accompanying drawings, the technical solution of the utility model is described in further detail.
Embodiment: a kind of short distance 3.5MHz channels watcher of the present embodiment, the control circuit comprising housing 1 and be arranged in housing 1.As shown in Figure 1; housing 1 is in cuboid; the end face of housing 1 is provided with upright antenna 21; the left side of housing 1, right side respectively have a cylinder protective cover 10 protruding, protrude left to the right; two protective covers 10 are near the top of housing 1; magnetic antenna L1 and magnetic antenna L2 is separately installed with in left side protective cover, right side protective cover; the left side of housing 1 is also provided with one and adjusts platform knob 11 and a volume adjustment knob 12, and the right side of housing 1 is provided with a push switch 13 and an earphone interface 7 with mains switch.As shown in Figure 2, control circuit comprises direction-finder antenna 2, high-frequency amplifying unit 3, adjustable signal generator based on heter rodyne action 4, difference frequency detection unit 5 and the audio amplification unit 6 be made up of audio frequency pre-amplifier unit 8 and Audio power amplifier unit 9, direction-finder antenna 2 is connected with the input of high-frequency amplifying unit 3, the output of high-frequency amplifying unit 3 and the output of adjustable signal generator based on heter rodyne action 4 are connected with the input of difference frequency detection unit 5 respectively, the output of difference frequency detection unit 5 is connected with the input of audio frequency pre-amplifier unit 8, the output of audio frequency pre-amplifier unit 8 is connected with the input of Audio power amplifier unit 9, the output of Audio power amplifier unit 9 is connected with earphone interface 7.
As shown in Figure 3, whole control circuit is powered by 6V battery BT, and K switch is mains switch, and earphone socket CK and K switch are realized by the earphone interface 7 with mains switch in Fig. 1.Direction-finder antenna 2 comprises upright antenna 21, single-direction and dual-direction change over switch S, phase modulation resistance R15, tuning capacitance C1 and the magnetic antenna L1 be coupled mutually and magnetic antenna L2, single-direction and dual-direction change over switch S are exactly the push switch 13 in Fig. 1; High-frequency amplifying unit 3 comprises triode T1, high unwrapping wire circle B1, adjustable resistance RP1, resistance R1 ~ resistance R4, electric capacity C2 ~ electric capacity C4 and electric capacity C19; Adjustable signal generator based on heter rodyne action 4 comprises beat oscillator coil B2, triode T3, variable capacitance diode D2, adjustable resistance RP3, voltage-stabiliser tube D3, resistance R10 ~ resistance R14, electric capacity C14 ~ electric capacity C18 and electric capacity C20; Difference frequency detection unit 5 comprises detection tube D1, the filter circuit be made up of electric capacity C5, electric capacity C6 and resistance R5 and detection load resistance R6; Audio frequency pre-amplifier unit 8 comprises triode T2, resistance R8, resistance R9, electric capacity C8 and electrochemical capacitor C10; Audio power amplifier unit 9 comprises adjustable resistance RP2, amplifier U, resistance R7, electric capacity C11, electrochemical capacitor C7, electrochemical capacitor C9, electrochemical capacitor C13 and feedback capacity C12.
Upright antenna 21 is connected with 2 pin (public pin) of single-direction and dual-direction change over switch S, 1 pin of single-direction and dual-direction change over switch S is through the series circuit ground connection of phase modulation resistance R15 and tuning capacitance C1, magnetic antenna L1 and tuning capacitance C1 is in parallel, 3 pin of single-direction and dual-direction change over switch S and the equal ground connection in one end of magnetic antenna L2, the other end of magnetic antenna L2 is connected with one end of electric capacity C2, the other end of electric capacity C2 is connected with the base stage of triode T1, the base stage of triode T1, one tunnel is through resistance R2 ground connection, a road is also had to be connected with the movable end of adjustable resistance RP1 through resistance R1, a stiff end ground connection of adjustable resistance RP1, another stiff end of adjustable resistance RP1 is connected with voltage V1 end, the emitter of triode T1 is through the parallel circuits ground connection of electric capacity C4 and resistance R3, the collector electrode of triode T1 is connected with one end of the primary coil of high unwrapping wire circle B1, the parallel connection of primary windings of electric capacity C3 and high unwrapping wire circle B1, the middle tap of the primary coil of high unwrapping wire circle B1 to be not only connected but also through electric capacity C19 ground connection through resistance R4 and voltage V1 end, one end of the secondary coil of high unwrapping wire circle B1 is connected with the positive pole of detection tube D1, the other end of the secondary coil of high unwrapping wire circle B1 is connected with one end of the secondary wire coil of beat oscillator coil B2, another termination voltage V2 of the secondary wire coil of beat oscillator coil B2 holds.In adjustable signal generator based on heter rodyne action, the collector electrode of triode T3 and the negative pole of voltage-stabiliser tube D3, a stiff end of adjustable resistance RP3 is connected and connects voltage B and holds, another stiff end of adjustable resistance RP3 meets voltage V2 through resistance R14 and holds, the positive pole of voltage-stabiliser tube D3 also meets voltage V2 and holds, the emitter of triode T3 meets voltage V2 through the parallel circuits of resistance R12 and electric capacity C18 and holds, electric capacity C17 and voltage-stabiliser tube D3 is in parallel, the movable end of adjustable resistance RP3 is connected with one end of electric capacity C20 and resistance R13, the other end of electric capacity C20 is connected with the negative pole of voltage-stabiliser tube D3, the other end of resistance R13 is connected with the negative pole of variable capacitance diode D2, the positive pole of variable capacitance diode D2 meets voltage V2 and holds, adjustable resistance RP3 is exactly the tune platform knob 11 in Fig. 1, one end of resistance R10 is connected with the collector electrode of triode T3, one end of electric capacity C16 is connected with the emitter of triode T3, the other end of resistance R10 and electric capacity C16 is all connected with one end of resistance R11, another termination voltage V2 of resistance R11 holds, the base stage of triode T3 is connected with one end of the primary coil of beat oscillator coil B2, the other end of the primary coil of beat oscillator coil B2 had not only met voltage V2 through electric capacity C14 and has held but also be connected with the negative pole of variable capacitance diode D2 through electric capacity C15.The negative pole of detection tube D1 had not only been connected through electric capacity C5 ground connection but also with one end of resistance R5, and the other end of resistance R5 to be not only connected with the base stage of triode T2 through electric capacity C8 but also through electric capacity C6 ground connection, detection load resistance R6 and electric capacity C6 is in parallel.The base stage of triode T2 is connected with the collector electrode of triode T2 through resistance R8, the grounded emitter of triode T2, the collector electrode of triode T2 had not only been connected through resistance R9 with voltage V1 end but also had been connected with the positive pole of electrochemical capacitor C10, the negative pole of electrochemical capacitor C10 had not only been connected through electric capacity C11 ground connection but also with a stiff end of adjustable resistance RP2, another stiff end ground connection of adjustable resistance RP2, the movable end of adjustable resistance RP2 is connected with the inverting input of amplifier U, the in-phase input end ground connection of amplifier U, voltage V1 end is connected with one end of resistance R7, the other end of resistance R7 had not only been connected through electrochemical capacitor C9 ground connection but also through the positive pole of K switch with battery BT, the output of amplifier U is connected with the positive pole of electrochemical capacitor C13, the negative pole of electrochemical capacitor C13 is connected with the positive pole of earphone socket CK, the minus earth of earphone socket CK, amplifier U is also connected with feedback capacity C12, in the present embodiment, amplifier U adopts LM386 operational amplifier, the positive pole of electrochemical capacitor C7 is connected with voltage V1 end, the minus earth of electrochemical capacitor C7, adjustable resistance RP2 and adjustable resistance RP1 adopts the coaxial duplex potentiometer controlled, it is exactly the volume adjustment knob 12 in Fig. 1.
When needing to survey large sound face, control single-direction and dual-direction change over switch S, its 2 pin and 1 pin are connected, then upright antenna and magnetic antenna L1 connect, adjustment tuning capacitance C1, make antenna loop resonance in 3.53MHz, the signal that upright antenna receives is coupled to magnetic antenna L2 by magnetic antenna L1, then flows to high-frequency amplifying unit.During the large sound face of accident, do not need access magnetic antenna L1, control single-direction and dual-direction change over switch S, its 2 pin and 3 pin are connected, then upright antenna directly and magnetic antenna L2 connect, the signal of upright antenna reception flows to high-frequency amplifying unit again by magnetic antenna L2.After direction-finder antenna receives the able one signal of 3.5 ~ 3.6MHz that radio station sends, deliver to high-frequency amplifying unit to amplify, difference frequency detection unit is added to together with the second harmonic of the oscillator signal of 1.75 ~ 1.8MHz that the signal after amplification and adjustable signal generator based on heter rodyne action produce, the frequency of adjustment signal generator based on heter rodyne action, it is made to produce the signal of 1KHz more high or low than Received signal strength, the output signal of this signal and high-frequency amplifying unit carries out difference frequency detection, obtain the low frequency signal of 1KHz, and then deliver to audio amplification unit and amplify, earphone is given finally by earphone interface, the telegraphic signal that sportsman just sends by earphone uppick radio station.Adjustable signal generator based on heter rodyne action adopts electric tuning mode, by regulating platform knob (adjustable resistance RP3), the bias voltage that change is added on variable capacitance diode D2 is to change the capacitance at variable capacitance diode D2 two ends, thus change frequency of oscillation, reach the object adjusting platform, play channel selection and beat effect simultaneously.By regulating volume adjustment knob, namely adjust adjustable resistance RP1 and adjustable resistance RP2 simultaneously, adjustment adjustable resistance RP1 can control highly to put level work point, reach the object controlling high amplification gain, channels watcher high level of putting when the strong signal in close-table district is made not occur choking phenomenon, still can maintain and amplify and keep good directivity normally, adjustment adjustable resistance RP2, can change the volume of the audio signal of output.
The utility model only uses an adjustable signal generator based on heter rodyne action, directly poor go out low frequency signal, play channel selection and beat effect simultaneously, do not have local oscillator level and in put level, eliminate intermediate frequency conversion and treatment circuit, circuit is simple, and cost is lower, uses flexibly, radio reception capability is strong, be adapted at match under the particular surroundingss such as mountain region to use, the scope of application is wide, meets the needs of direction-finding station campaign under various environment.
Claims (8)
1. a short distance 3.5MHz channels watcher, it is characterized in that the control circuit comprising housing (1) and be located in housing (1), control circuit comprises direction-finder antenna (2), high-frequency amplifying unit (3), adjustable signal generator based on heter rodyne action (4), difference frequency detection unit (5) and audio amplification unit (6), direction-finder antenna (2) is connected with the input of high-frequency amplifying unit (3), the output of high-frequency amplifying unit (3) and the output of adjustable signal generator based on heter rodyne action (4) are connected with the input of difference frequency detection unit (5) respectively, the output of difference frequency detection unit (5) is connected with the input of audio amplification unit (6), the output of audio amplification unit (6) is connected with earphone interface (7).
2. a kind of short distance 3.5MHz channels watcher according to claim 1, it is characterized in that described audio amplification unit (6) comprises audio frequency pre-amplifier unit (8) and Audio power amplifier unit (9), the input of audio frequency pre-amplifier unit (8) is connected with the output of described difference frequency detection unit (5), the output of audio frequency pre-amplifier unit (8) is connected with the input of described Audio power amplifier unit (9), and the output of Audio power amplifier unit (9) is connected with described earphone interface (7).
3. a kind of short distance 3.5MHz channels watcher according to claim 1, it is characterized in that described adjustable signal generator based on heter rodyne action (4) comprises beat oscillator coil B2, triode T3, variable capacitance diode D2, adjustable resistance RP3 and voltage-stabiliser tube D3, the collector electrode of triode T3 and the negative pole of voltage-stabiliser tube D3, a stiff end of adjustable resistance RP3 is connected and connects voltage B and holds, another stiff end of adjustable resistance RP3 meets voltage V2 through resistance R14 and holds, the positive pole of voltage-stabiliser tube D3 also meets voltage V2 and holds, the emitter of triode T3 meets voltage V2 through the parallel circuits of resistance R12 and electric capacity C18 and holds, electric capacity C17 and voltage-stabiliser tube D3 is in parallel, the movable end of adjustable resistance RP3 is connected with one end of electric capacity C20 and resistance R13, the other end of electric capacity C20 is connected with the negative pole of voltage-stabiliser tube D3, the other end of resistance R13 is connected with the negative pole of variable capacitance diode D2, the positive pole of variable capacitance diode D2 meets voltage V2 and holds, one end of resistance R10 is connected with the collector electrode of triode T3, one end of electric capacity C16 is connected with the emitter of triode T3, the other end of resistance R10 and electric capacity C16 is all connected with one end of resistance R11, another termination voltage V2 of resistance R11 holds, the base stage of triode T3 is connected with one end of the primary coil of beat oscillator coil B2, the other end of the primary coil of beat oscillator coil B2 had not only met voltage V2 through electric capacity C14 and has held but also be connected with the negative pole of variable capacitance diode D2 through electric capacity C15, one end of the secondary wire coil of beat oscillator coil B2 is connected with the input of described difference frequency detection unit (5), another termination voltage V2 of the secondary wire coil of beat oscillator coil B2 holds.
4. a kind of short distance 3.5MHz channels watcher according to claim 1 or 2 or 3, it is characterized in that described difference frequency detection unit (5) comprises detection tube D1, by electric capacity C5, the filter circuit that electric capacity C6 and resistance R5 is formed and detection load resistance R6, the positive pole of detection tube D1 is connected with the output of described high-frequency amplifying unit (3), the negative pole of detection tube D1 had not only been connected through electric capacity C5 ground connection but also with one end of resistance R5, the other end of resistance R5 had not only been connected with the input of described audio amplification unit (6) but also through electric capacity C6 ground connection, detection load resistance R6 and electric capacity C6 is in parallel.
5. a kind of short distance 3.5MHz channels watcher according to claim 2, it is characterized in that described high-frequency amplifying unit (3) comprises triode T1, high unwrapping wire circle B1 and adjustable resistance RP1, the base stage of triode T1, one tunnel is connected with the output of described direction-finder antenna (2) through electric capacity C2, another road is through resistance R2 ground connection, a road is also had to be connected with the movable end of adjustable resistance RP1 through resistance R1, a stiff end ground connection of adjustable resistance RP1, another stiff end of adjustable resistance RP1 is connected with voltage V1 end, the emitter of triode T1 is through the parallel circuits ground connection of electric capacity C4 and resistance R3, the collector electrode of triode T1 is connected with one end of the primary coil of high unwrapping wire circle B1, the parallel connection of primary windings of electric capacity C3 and high unwrapping wire circle B1, the middle tap of the primary coil of high unwrapping wire circle B1 to be not only connected but also through electric capacity C19 ground connection through resistance R4 and voltage V1 end, the secondary coil of high unwrapping wire circle B1 is connected with the input of described difference frequency detection unit (5).
6. a kind of short distance 3.5MHz channels watcher according to claim 5, it is characterized in that described audio frequency pre-amplifier unit (8) comprises triode T2, described Audio power amplifier unit (9) comprises adjustable resistance RP2 and amplifier U, the base stage of triode T2 had not only been connected through electric capacity C8 with the output of described difference frequency detection unit (5) but also had been connected with the collector electrode of triode T2 through resistance R8, the grounded emitter of triode T2, the collector electrode of triode T2 had not only been connected through resistance R9 with voltage V1 end but also had been connected with the positive pole of electrochemical capacitor C10, the negative pole of electrochemical capacitor C10 had not only been connected through electric capacity C11 ground connection but also with a stiff end of adjustable resistance RP2, another stiff end ground connection of adjustable resistance RP2, the movable end of adjustable resistance RP2 is connected with the inverting input of amplifier U, the in-phase input end ground connection of amplifier U, voltage V1 end is connected with one end of resistance R7, the other end of resistance R7 had not only been connected through electrochemical capacitor C9 ground connection but also through the positive pole of K switch with battery BT, the output of amplifier U is connected with the positive pole of electrochemical capacitor C13, the negative pole of electrochemical capacitor C13 is connected with the positive pole of earphone socket CK, the minus earth of earphone socket CK, amplifier U is also connected with feedback capacity C12, adjustable resistance RP2 and adjustable resistance RP1 adopts the coaxial duplex potentiometer controlled.
7. a kind of short distance 3.5MHz channels watcher according to claim 1 or 2 or 3, it is characterized in that described direction-finder antenna (2) comprises upright antenna (21), the magnetic antenna L1 of single-direction and dual-direction change over switch S and coupling mutually and magnetic antenna L2, upright antenna (21) is connected with the public pin of single-direction and dual-direction change over switch S, the haptic element of single-direction and dual-direction change over switch S is through the series circuit ground connection of phase modulation resistance R15 and tuning capacitance C1, magnetic antenna L1 and tuning capacitance C1 is in parallel, another haptic element of single-direction and dual-direction change over switch S and the equal ground connection in one end of magnetic antenna L2, the other end of magnetic antenna L2 is connected with the input of described high-frequency amplifying unit (3).
8. a kind of short distance 3.5MHz channels watcher according to claim 7, it is characterized in that described housing (1) is in cuboid, the end face of housing (1) is located at by described upright antenna (21), the left side of housing (1), right side respectively has one to protrude left, the cylinder protective cover (10) protruded to the right, two protective covers (10) are near the top of housing (1), described magnetic antenna L1 and magnetic antenna L2 lays respectively at left side protective cover (10), in right side protective cover (10), the left side of housing (1) is provided with adjusts platform knob (11) and volume adjustment knob (12), described single-direction and dual-direction change over switch S adopts push switch (13), push switch (13) is located at the right side of housing (1), described earphone interface (7) adopts the earphone interface with mains switch, earphone interface (7) is located at the right side of housing (1).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520424880.5U CN204795565U (en) | 2015-06-18 | 2015-06-18 | Short distance 3. 5MHz radio direction finding machine |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520424880.5U CN204795565U (en) | 2015-06-18 | 2015-06-18 | Short distance 3. 5MHz radio direction finding machine |
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| Publication Number | Publication Date |
|---|---|
| CN204795565U true CN204795565U (en) | 2015-11-18 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
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| CN201520424880.5U Withdrawn - After Issue CN204795565U (en) | 2015-06-18 | 2015-06-18 | Short distance 3. 5MHz radio direction finding machine |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105101012A (en) * | 2015-06-18 | 2015-11-25 | 鲁晓阳 | Short-distance 3.5MHz radio direction finder |
-
2015
- 2015-06-18 CN CN201520424880.5U patent/CN204795565U/en not_active Withdrawn - After Issue
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105101012A (en) * | 2015-06-18 | 2015-11-25 | 鲁晓阳 | Short-distance 3.5MHz radio direction finder |
| CN105101012B (en) * | 2015-06-18 | 2018-07-31 | 鲁晓阳 | Short distance 3.5MHz channels watchers |
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