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1W FM stereo transmitter circuit

This article describes 1W FM stereo transmitter unit from the audio modulation circuits and radio frequency modulated wave amplification circuit unit composed of two parts. Audio modulation unit circuits of the two IC, debugging becomes extremely simple. Modulated wave RF amplifier circuit of the main vibration level off with crystal frequency stabilization, the phase modulation circuit after another in the oscillator circuit, so the machine high frequency stability. Harmonic-class LC resonant circuit with selective frequency pass band and rectangular coefficient is small, with a good pair of special frequency selective frequency tuning circuit, the resonant frequency of the spurious unwanted harmonic outside a huge extent. The final amplifier output connected multi-section band-pass, low pass filter so that the wireless radio waves transmitted out one more pure, even if the TV is also close to work would not be disturbed. Is a generic for lovers of high-performance radio communications transmitter. Circuit as shown. Audio modulation circuits use high quality dual pre-amplifier IC1 price qian Jiang Sheng op amp NE5532. Li Hugh acoustic signal integrated circuit IC2 use NNJM2035D. To poker machines dynamic microphones or CD were from high-fidelity audio signals L, R-ended input, by W1, W2 coaxial potentiometer control input signal after the voltage range for high fidelity amplification into IC1. IC2 has ○ 1 foot, ○ 14 feet for the stand off-sound audio signal input through the internal functions of this IC circuit after a series of processing the output from the synthesis ○ 9 feet stand off acoustic signal. This signal ○ 8-pin output 19KHZ pilot signal superimposed by the W3 choose the right amount of signal sent to the RF circuit components of the phase after the transfer level. The main transmitter from the crystal vibration level V1, the composition components such as crystal JX2. Oscillation frequency FO = 15.3MHAZ. V2 is a buffer amplifier stage, the output signals coupled to phase modulation by the T1 level, to be its audio signal to modulate. Varactor diode D2, inductor T2, resistors R24, R25, R26 phase modulator composed of bridge. R24, R25, R26 phase modulator, respectively bridge the three bridge arms, the fourth leg from the T2, D2 form. Audio modulation signal by C20, R18 added to the fourth leg. PM FM signal generated by the C30 sent to V3, V4 buffer amplified by T3, C34, C35, T4, C36, C37 consisting of selected double-tuned frequency selection circuit 3 times FO sine wave signal that FO × 3 = 15.3 × 3 = 45.9MHZ. V5 This secondary harmonic frequency signal amplified by the T5, C39, C40, T6, C41, C42 composed of double-tuned frequency selection circuit selected (45.9 × 2 = 91.8MHZ) second harmonic signal is sent to the V6 to power amplifier. V6 output RF amplifier signal by L2 ~ L5, C45 ~ C54 consisting of band-pass, low pass (and impedance matching) filter filter out unwanted harmonics can be carried to the antenna radiation radio waves to the surrounding space. Production, the audio circuit and the RF modulation unit cell circuit to be produced in two circuit boards, respectively. RF unit circuit shielding measures should be taken as a whole. W1, W2 for the coaxial volume potentiometer, IC1 use of inexpensive and quality Liangsheng op amp NE5532. IC2 use NJM2035D. JX1 use 38kHZ crystal. Use an ordinary light-emitting diode D1. W3 fine-tuning for the 10K resistor. R1 ~ R18 choose 1/16W colored ring of metal film resistors. C1 ~ C21 use high-quality capacitors. JX2 use 15.3MHZ crystal. C23, C46, C47 are 5/25PF high-frequency fine-tuning capacitor. V1, V2, V3 use 22SC2787, V4, V5 choose 22SC2026. V6 used 22SC2538, the control parameters: PCM = 3W, ICM = 0.4A, FT = 175MHZ. Varactor diode D2 use IIS2236. C23 ~ C56 than C42, C56 for the high-quality electrolytic capacitors, the other tiles are high-frequency capacitor. R19 ~ R38 ordinary use 1/8W carbon film resistors, R39 use 1W carbon film resistors. T1 ~ T6 are in the 7 × 7 high frequency in the week made the wound, T1 high-frequency primary Φ0.21mm enameled wire with 1 to 3 slot in the winding 6 turns, the secondary tank in the first 3 Turn around 3; T2 high frequency with Φ0.21mm enameled in paragraphs 1, 2 slot all around 9 turns; T3, T4 enameled with Φ0.38mm high-frequency slots in the first 1 to 3 turns each around 2; T5 , T6 high-frequency enameled with Φ0.38mm 2 to 3 slot in around two turns each. L1 ~ L5 is the diameter of 3.5mm enameled wire core high-frequency inductors, high frequency are used Φ0.51mm made of enameled wire wound, L1 around 5 turns, L2 4 turns around, L3 around 5 turns, L4 3 turns around, L5 Turn around 5. IC3 use LM78L067. Antenna with double cross-shaped omni-directional antenna, to stand at more than 10 meters above the ground high quality coaxial cable with 75-5 lead to the RF output of this machine can. Debug circuit should first access 75Ω RF output frequency false load resistance to prevent damage to the RF power when the load control V6. High voltage meter measured at V2’s collector voltage of 2V that high-frequency vibration from the normal V1, the test with a frequency meter measuring stick point V2 of the collector, the use of non-sense of a small screwdriver to adjust the fine tuning capacitor C23 value for the frequency counter display “15.300MHZ” that completed a LO buffer amplifier stage of debugging. High Frequency Voltage measured in V4 of the collector voltage of 5V high frequency that V3, V4 buffer amplifier stage is working properly. Adjust the T3, T4’s core high-frequency voltage to the base table on the V5 to the high rate of total measured value is displayed as “45.900MHZ” that completed a three-frequency circuit debugging. Adjust the T5, T6 of the core so that the base V6, the frequency counter display value as “91.800MHZ” which completed the second harmonic circuit debugging. Mapping of High Frequency Voltage point marked A high frequency voltage, adjust the fine tuning capacitor C46, C47 to A point of high-frequency voltage ≥ 12V. Mapping of High Frequency Voltage point marked B in the high-frequency voltage, with no sense of a flat screwdriver Toggle L3, L4, L5 to turn away, so that B points, the high frequency voltage ≥ 10V, frequency meter probe in the distance false load 10 ~ 20cm away sensing, frequency meter display value as “91.800MHZ” stability constant that is completed L3 ~ L5, C49 ~ C54 consisting of band-pass, low pass filter preliminary test. Remove the false load access antenna Field emission experiment, I found that the output power ratio of access to fake the output power of a small load. Mainly in the B point for the diagram of low voltage high frequency of many shows at this time of the antenna impedance less than 75Ω. Flat with no sense of a small screwdriver were Toggle L3, L4, L5’s turn away from, so that B points to the high-frequency test voltage ≥ 10V is completed V6, L2 ~ L5 level components, such as wiping the composition of formal power amplifier output circuit debugging. Audio modulation circuit debug module and FM stereo radio Yang be combined with the conduct. L, R into the CD machine end of high-fidelity audio output signal, and then hand-held FM stereo radio to listen to a certain distance. Input to the L, R end of the signal amplitude is too strong, the receiver hears the noise signal is turbid, then counter-clockwise adjustment W1, W2 are knob until the receiver to hear the right sound signals clearly identified date. If listening to the voice signal and restore the limiting distortion, the FM modulator bias potentiometer W3, until the receiver came up the sound signal fidelity reproduction. After more debugging, you can hand to test the FM stereo radio emission from the. Receiver sensitivity of 500μV with ordinary FM stereo radio receiver, the open land around 1.5km distance, non-open to a distance of about 500m, FM stereo indicator light properly. The receiver sensitivity 0.5μV senior FM stereo radio receiver, the open field from more than 5km, and the stereo indicator light is still normal.

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51 Responses

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  5. Austin DWI Lawyer 2014/01/28 at 12:31:53

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    • admin 2014/02/17 at 08:05:58

      hello friend,
      I am so sorry, this is just a share
      we don’t have this product
      Best regard
      lanyue

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    • admin 2014/02/12 at 06:23:11

      hello friend,
      I am sorry, it just a artical
      just for share
      best regard
      lanyue

  7. facebook marketing 2014/02/20 at 07:47:52

    hello, I want to built a broadcasting station, could you recommend some transmitter? and I need to know what else product I have to buy
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    • admin 2014/02/21 at 04:03:26

      Hello friend,
      could you tell me your E-mail?
      I would send you in E-mail
      Best Regard
      lanyue

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      hello friend,
      yes, we have it in stock,
      could you send me E-mail?
      best regard
      lanyue

  9. weight loss remedies 2014/02/28 at 15:42:27

    hello, I need to buy a tv transmitter, but I don’t know which is suit for me

    • admin 2014/03/01 at 06:27:51

      hello, friend
      could you send me E-mail?
      best regard
      lanyue

  10. www.jewishgen.org 2014/03/04 at 18:35:11

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    • admin 2014/03/07 at 03:47:05

      hola, amigo.
      Sí, ofrecemos componente, por lo que ¿Cuál quieres?
      podría u enviarme un e-mail? gracias.
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  11. 3d printing companies 2014/03/09 at 22:05:46

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  12. 3-d printing 2014/03/09 at 22:23:43

    Hello mates,
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    • admin 2014/03/12 at 01:26:30

      hello friend,
      could u send me E-mail?
      I will teach you in E-mail
      best regard
      lanyue

  13. jillian michaels body revolution 2014/03/15 at 06:44:30

    I’m glad I found that product
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    • admin 2014/03/18 at 10:21:26

      hello friend,
      how many product do you want?
      you can send me E-mail
      best regard
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  14. marry 2014/04/16 at 13:41:35

    Please let me know if you if you got some microphone in stock.

  15. Stephen 2014/04/20 at 16:45:47

    hello, I have a custormer wants to see the low power transmitter, could she visit your office?

    • admin 2014/04/21 at 06:36:44

      hello, stephen
      yes, welcome to visit us,
      Address: FMUSER
      No.1502 Room HuiLan Building No.273 Huanpu Road Tianhe District Guangzhou China Zip:510620
      E-mail: [email protected]
      Web:www.czhfmtransmitter.com

      Skype:lanyue99991 QQ:448122256

  16. david 2014/04/20 at 18:35:37

    I appreciate the sample product you sent me, I am going order more
    but I wish you can give me lower price.

    • admin 2014/04/21 at 06:40:44

      hello David,
      if you buy more I can give you discount.
      send me the quantity you want in E-mail
      I would reply soon
      Best regard
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  20. Arthur 2014/04/29 at 05:57:48

    hello admin, I want to know how to set the antenna

  21. steven 2014/05/05 at 04:09:06

    Can I use western union to pay? pls tell me your account NO.

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    • admin 2014/05/06 at 02:17:36

      Hello steven
      yes, you could use western union
      and this is our account
      Full name: Quan Li
      First name/Given Name: QUAN
      Last name/ Surname: LI
      Country: China
      City: Guangzhou

      Best Regard
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  22. Michael Kors 2014/05/15 at 00:14:48

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    • admin 2014/05/19 at 03:46:18

      hello Michael Kors
      yes we have gp antenna in stock,
      we have 1/2 wave and 1/4 wave gp antenna, which one do you prefer?
      you can send me e-mail
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  23. luka 2014/05/18 at 02:11:43

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    • admin 2014/05/19 at 03:15:36

      hello Luka
      western union is ok
      thank you very much
      Best Regard
      lanyue

  24. Kelvin 2014/05/19 at 13:26:46

    Thanks for shipping the product
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    • admin 2014/05/20 at 02:03:46

      Hello Kelvin
      the tracking NO. has been sent in E-mail
      please cheak you E-mail
      Best Regard
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  25. julian 2014/05/20 at 08:45:31

    I’m planning to start my own studio.
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    • admin 2014/05/21 at 01:30:55

      hello julian
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      please click your e-mail
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  26. mack 2014/05/22 at 21:29:16

    Do you have the tracking number?
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    • admin 2014/05/27 at 02:26:31

      hello mack
      I have sent tracking number in e-mail to you.
      please check your e-mail
      Best regard
      lanyue

  27. yuki 2014/05/22 at 21:38:56

    dear lanyue
    I already received your transmitter
    Thank you for shipping

    • admin 2014/05/27 at 02:48:09

      It’ my pleasure

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