The frog sounds Micro telegraph transceiver kit manual A brief introduction This is a very small volume of a simple 40 meter band micro-power amplitude telegraph transceiver, 9V square battery or external 9-12V DC power supply. Spread good time, and the nearby provinces hundreds of kilometers amateur radio communications. This machine was first introduced by domestic radio enthusiasts, but also it played a nice name "frogs". The frogs calling Kit 3.1 public version based, combined with the actual usage Fixed several key issues, after several debugging before the formation of the current version. Key Indicators Power supply: 9V-12V (Recommended 12V linear regulated power supply) Antenna: 50 ohm, unbalanced Transmission power: 2W (9V Power), 3W (12 power) Frequency: transmitter local oscillator frequency: 7023KHz; receive local oscillator frequency: about 7023-7026KHz Operating mode: CW Circuit schematic See last page of this document accompanying drawings, the receiving part of the core is an NE602, including its internal oscillation circuit and a balanced mixer the antenna signal coming into the mixer after a crystal filter and attenuation potentiometer, The oscillation circuit in the reception frequency oscillation, the two signals after the mixer, directly at the SSB / CW signal is converted to an audio output audio NE602 gave LM386 zoom back, thus completing the whole process. By direct mixing the RF signal into audio receiver is called the "DC receiver, the DC mean direct conversion. LM386 amplifies the output speech signal, by the 2N7000 FET constituting the mute circuit is used to turn off the receiver in the time when transmitting, at the same time the 74HC00 which the audio oscillator generating sidetone, to make with headset Follow produce drops pattered keying the audio. Emitting portion using NE602 oscillation circuit, then buffer amplifier 9018, and 9018 as a transmission key, the control transceiver circuit and the signal switching, the final stage is constituted by the D882 Class C amplifier, the amplified high-frequency signal through the LPF filtering followed antenna. Component selection 9018 magnification select 130 D882 of about 200 magnification selection. L4 is a high-frequency choke on FT37-43 ferrite bead (black) 0.51mm enameled wire around 11 laps, approximately 20cm (can also be used the fixed inductor instead) for sale on the market, the inductance of about 20uH. L5 is a high-frequency filter inductor 0.51mm enameled wire or mesh wire wound on a magnetic iron core T37-2 (red), 16 laps, about 25cm, the inductance in 1uH about. Other Inductance: 1mH fixed color ring inductance 100mH inductance the cylinder fixed inductors, outsourcing black heat shrink tubing. Less than 1000pF capacitor for high frequency ceramic the 0.47uF capacitor for monolithic capacitors, larger than 1uF capacitor aluminum electrolytic capacitors, all resistance fixed resistor 1/4W 5%.
Production testing Install all components, first of all transistors, resistors, capacitors with a multimeter test again. Then control the logo to install all the components of the circuit diagram and PCB board. Generally installed in accordance with the order from low to high. After welding, must check for solder short circuit. Package MOS FET 2N7000, in order to prevent electrostatic breakdown, soldering iron should be properly grounded or disconnect the power to the soldering iron, waste heat welding. Integrated circuit mounted socket, which can effectively avoid the core of the integrated circuit welding bad. Everything is in order, check and correct the positive and negative polarity connected to the power supply, the power supply must not pick the wrong. Inserted into the headphone jack, Walkman headphones, you can hear white noise. On the termination of the antenna 51 ohm resistor false load, shorted KEY (to simulate pressing the key), detection machine current should not exceed 150mA. Not a long shorted KEY launch, otherwise D882 and dummy load fever, accidentally damage. Termination on the antenna, the antenna should be able to hear the noise gets louder or CW signal, rotating board is indeed 47K potentiometer CW signal tone should change from high to low. Use This machine is a simple direct conversion transceiver interference, selectivity can be compared and the superheterodyne receiver, it is necessary to use not worse than the length of a half-wave dipole antenna, or communication is relatively poor. The selection disturbance is relatively small, spread the good opportunity for communication experiment, it is best to make an appointment with your friends communication. Communication distance of about 150-300 km more secure, to greater distance depends on the propagation environment and the operator's operating skills. If the broadcast interference is relatively large, use 5K GAIN potentiometer signal attenuation, emergent signal from the radio interference. Attenuation potentiometer is critical, carefully adjusted, you will receive an unexpected effect. In the dissemination of good times with of this machine FT80C goods shortwave radio with a signal on a distant contrast reception, this local effect is no difference between basic commodity machine, which makes unexpected. Recommendations for improvement 1N4001 replaced by appropriate varactor tube (recommended the 0P-100P), can increase the receive frequency range. Q1 9018 power between 0.8W ~ 1.2W 8050 power between 1.5W to 2W (select 8050 will make D882 In a critical state, need to be careful). Finally, I hope you DIY machine, can be a successful!
The list of components 1/4W fixed resistor Electrolytic capacitors R1 200 CP1/CP7 100uf/16v R6/R13 150k CP2/CP5/CP6/ 10uf/16v CP8/CP9 R3/R4/R12 10K CP3/CP4 47uf/16v R5 100K CP10 1uf/16v R7/R8 10 Transistor R9 47k D1/D2/D5/D7 1N4148 R2 220K D3/D6 1N4001 R11 39 Q1 9018 OR 8050 R10/R14/R15/R23 1K Q2 2N7000 Adjustable resistance Q3 D882 W2 47k(473) Q4 8550 W1 4k7 LED1 Red LED Fixed inductors L1 100mH(8*10 工 IC Shape) L3 1mH (color U1 78L06(T092) ring inductance) L4 22uH (magnetic) U2 NE602(DIP8) L5 1uH (magnetic) U3 LM386(DIP8) Ceramic capacitors U4 74HC00(DIP14) C7/C12/C13/C14/C16/C20 0.1uF(104) Crystal C1/C3/C6/C9/C11/C15 0.01uF(103) Y1/Y2 7.023MHz C2 22pf Other components C4/C5/C10 82pf J2 Green 2P Wiring Block C8 0.47uf(474) J4 Black power outlet C17/C18 470pf(471) J3 3.5mm Stereo Jack (KEY) C19 4700pf(472) J1 3.5mm StereoJack(PHONE) Diameter of 0.51mm enameled wire for PCB circuit board * 1 some In addition, with the kit as well as a 51 ohm refers 1W resistor used to act as a dummy load for testing. Note: LM386 due to different manufacturers, there will be such the GM386, KA386, JRC386 are LM386 compatible models! BOARD ASSEMBLY
Please note that Q3 (D882) direction, pin1 square hole.own Q3 actual use, plus a "U"-shaped fins, the assembly of the space at the rear of the device are sufficient. The identification of the color ring resistance ceramic capacitors Color ring resistance, the most common accuracy of 5% and 1% accuracy, 5% accuracy for 4 color wheel, 1% accuracy of the five-color rings, read The method is as follows: Capacitance of ceramic capacitors generally made pf (10R -12 power F) units, some products using direct labeling, such as 1000p, 220p : To index notation, such as: 102,221, the first two digits are the significant figures of the capacitance after a number is followed by adding a zero The number, such as 102 effective number of 10,2 indicates that the following Adds 2 0 1000pF; 221 is effective mathematical 2,1 said Surface by putting 1 0, i.e. 220pF. Marked 62 62pF marked 102, 1000pF The polarity of the electrolytic capacitor Electrolytic capacitor positive and negative polarity, insert the PCB board installation, make sure that the positive and negative corresponding correct, do not install the wrong. Red red LED, long pin is positive, the short pin negative magnetic coils wound This package contains two magnetic ring: FT37-43 and T37-2. Do not wound them wrong. FT37-43 exterior color is black. T37-2 appearance color is red.