Install all the components before the first all transistors, resistors, capacitors with a multimeter test again. Then install the control circuit sche

Transcription

1 Frog sounds micro telegraph transceiver kit instructions Brief introduction This is a very small 40 meter band magnitude telegraph micropower transceiver, a 12V DC power supply, spread the good can be hundreds of kilometers away, and amateur radio communications. The machine was first introduced to China, China's radio enthusiasts played a good name "frog." Frogs kit with 3.1 public version, combined with the actual use of discovered several key issues, after several debugging, the formation of the current version. Key Indicators Power supply: 12V (Recommended linear regulated power supply) Antenna: 50 ohm, unbalanced Emission current: 400mA Transmit Power: 1.8W Frequency: The transmitter local oscillator frequency: 7023KHz; receive local oscillator frequency: about KHz Operating mode: CW Circuit principle See circuit diagram of the receiving part of the core is NE602, including its internal oscillation circuit and a balanced mixer, the antenna signal through the crystal filter and attenuator potentiometer, the access to the mixer, the oscillation circuit oscillates at the receiving frequency, these two signals through the mixer directly to the SSB / CW signal conversion audio, NE602 LM386 sending output audio amplification, thus completing the receiving process. The audio signal obtained by direct mixing of the receiver is called "DC Receiver", DC direct conversion means. Circuit by the D1, D5 constitutes an electronic switching circuit and Q7 constitute mute circuit is used in the transmitter off the receiver, while the audio oscillator Q4 constitute approximately 700Hz sine wave sidetone, gave LM386 enlarge, the headset with the beat Hair drops pattered generated audio. Transmitting part of the use of the oscillation circuit NE602, Q6 is buffered and then amplified by the final stage D882 Class C amplifier, the amplified high-frequency signal to the antenna through the LPF filtering. Components Selection 8050 magnification selection 130, D magnification selection. L3 in the FT37-43 (black) is a ferrite bead, and with 0.51 mm enameled wire around 11 laps. L4 is a high-frequency filter inductors, the magnetic core T37-2 (red), with a 0.51 mm enameled wire around 16 laps. Other inductors: 1MH 22uH is fixed color ring inductance; 100MH inductance is fixed inductors, outsourcing black heat shrink tubing. Frequency ceramic capacitor 0.47μF is monolithic capacitors; Greater than 10uF capacitors are electrolytic capacitors; resistance 1/4W 5% of all fixed resistors. Production Test

2 Install all the components before the first all transistors, resistors, capacitors with a multimeter test again. Then install the control circuit schematic PCB board all identified component. Generally in accordance with the order from low to high installation. After soldering, solder joints must be checked whether there is a short circuit. IC socket should be installed, which can effectively prevent the core IC bad welding. After checking there is no problem, connect the power, the power pole will certainly not be wrong. Headphone jack into the Walkman headphones, you should be able to hear white noise. Termination on the antenna 51 ohm resistor false load, short circuit KEY (simulates pressing key), testing machine current should not exceed 400mA. Avoid prolonged shorting KEY launch, or D882 and dummy load fever large, carefully damaged. Termination on the antenna in the antenna should be able to hear the noise becomes larger or have a CW signal, rotate the board 4.7K potentiometer, CW signal tone should change. When debugging, crystal shell first not grounded. In the receiving state touch Y1 shell, headphones noise becomes larger means receiving normal. Note: Be sure not no dummy load or antenna is not connected to the case supporting the launch, otherwise it will damage the circuit. Use The machine is a simple direct conversion transceiver circuit, anti-jamming capability, selectivity, as superheterodyne receiver, you want to use is not worse than the length of a half-wave dipole antenna, otherwise the effect of relatively poor communication. Select disturbance moving relatively small and spread good time, it is best friends with your reservation. Communication distance of about km more secure, longer distance depends on the propagation environment and operator skills.

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