Low-resistance three-tube radio DIY kit straight to regenerate circuit board assembly parts electronic production single tube

Model 1: Host kit (without headset battery)

Model 2: Host finished product (without battery earphones)

This three-tube earplug radio is improved on the basis of traditional circuits, with relatively complete functions, easy to obtain materials, easy to assemble successfully, and higher sensitivity than the general three-tube machine circuit.

【Product name】Low-resistance earplug three-tube radio assembly kit (Model_3TD-B1, Ver_1.0)

【Main Features】

1. Broadcasting system: Amplitude Modulation (AM);

2. Receiving frequency band: 525~1605kHz (medium wave MW);

3. Power supply mode: 3V DC (2 AA alkaline batteries);

4. Output impedance: 8~32Ω;

5. Host size: 90mm×70mm×28mm.

【Features】

This kit circuit (hereinafter referred to as this circuit) is improved on the basis of our 3TD-B classic three-tube machine, and has the following characteristics:

1. Using three 9014 super-beta silicon NPN transistors, it is easy to obtain materials;

2. Traditional regenerative circuit, germanium diode voltage doubler detection, high component utilization efficiency;

3. There is a light-emitting diode voltage regulator circuit, which improves the voltage adaptability of the high-amp circuit;

4. The high discharge tube uses a potentiometer to control the static current, which is convenient for adjustment. Players can also use it to balance the sensitivity and selectivity;

5. Since the volume of the circuit is very high, an internal volume potentiometer is set for this purpose to prevent the hearing damage caused by the volume being too large and unable to be adjusted;

This circuit has the advantages of high sensitivity, good selectivity, and loud and pleasant sound. It is suitable for electronic hobbyists and interested students and friends with a certain foundation.

Note: The shell has two colors: black and white. The default is white. If you need a black shell, please contact the owner or leave a message.

【product description】

1. This circuit is modified and designed according to the traditional three-tube earplug radio circuit. It belongs to the direct-play radio, and the working principle of the regenerative type. It is a simple radio circuit with fewer components and is easy to make. Ideal equipment for friends to explore scientific knowledge;

2. This circuit is an AM radio, which can receive medium wave broadcasts, but cannot receive short wave and FM broadcasts;

3. This circuit is designed to use low-impedance headphones for playback, and the impedance is suitable in the range of 8~32Ω. Such as external speakers or speakers can also hear the sound, but the volume is low. You can choose to use common stereo headphones or old-fashioned mono headphones with jumpers on the board;

4. The circuit board is designed with wiring for the regeneration circuit, but the antenna coil provided by the kit does not contain a regeneration coil. This part of the coil needs to be determined by the player according to the actual situation and wound by himself. Because the performance of this circuit is better without regeneration, and regeneration is difficult to control, it also has some side effects on sound quality, so it is not recommended to use;

5. This circuit is designed to use 2 AA alkaline batteries with a supply voltage of 3V. If two 1.2V nickel-cadmium and nickel-metal hydride batteries are used, it is best to readjust the parameters of the relevant components. Do not install the AAA lithium battery, because the voltage of one section is 3.7V, which will burn the circuit components;

6. The switch of the main unit is integrated with the socket. When the plug is inserted, the power is turned on, and when the plug is unplugged, the power is turned off and no power switch is required;

7. The base of the circuit board is glass fiber material, the thickness is measured about 1.5~1.6mm, the green oil is white, the pad is sprayed with tin, and it can be directly welded without grinding;

8. The circuit board obtained by the buyer may be slightly different from the sample in the picture, mainly due to the change of the component position and the adjustment of the symbol text mark, and the circuit structure will not change greatly. This product has been modified and perfected (mainly modifying the wiring of the circuit board) for n times from the trial-produced samples to the sold products, and is still in the process of continuous improvement. Usually, minor version upgrades will not be re-photographed and uploaded. Hereby declare ;

9. Regarding the identification of the appearance of the components and the interpretation of the parameters, please refer to the relevant materials for the primary players;

10. Players need to bring their own basic test instruments such as a multimeter, as well as tools such as screwdrivers, pliers, tweezers, soldering irons, and welding materials;

11. The manual provides the basic description of the function, installation, and usage of this product. The principle of the radio and the comprehensive debugging procedures are not within the scope of the manual. Friends who need these contents, please search for relevant literature for learning. ;

12. The specific content of this kit is subject to the content list of the kit at the time of shooting, and the specific technical details are subject to the contents in the manual provided by the kit.

【Illustration and text】