Dimensions: 125 × 68 × 28mm
Operating voltage: 3V (2pcs AA batteries, not contain)
Frequency Coverage: 535-1605KHz
The assembly instructions:

The spare parts for this teaching are 3V low-voltage all-silicon six-tube superheterodyne radio, which has the advantages of convenient installation, stable operation, loud sound, and low power consumption. It consists of an input loop high-level mixing stage , a first-stage amplifier, a second-stage amplifier, a front low-level amplifier, a detector stage, a low-level amplifier stage, and an amplifier stage. The receiving frequency range is from 535 kHz to 1605 kHz. Medium band . The design of this circuit and the selection of component parameters have been identified and approved by professional radio engineers. In addition to further learning of electronic technology in the process of assembly of components, it is also possible to grasp the electronic installation process, to know the measurement and debugging technology, and to get more results in the process. Please read this manual carefully before welding, which will greatly help your own theory and actual installation.

 

1. Component Description:
1) Three intermediate frequency transformers (hereafter referred to as "Zhong Zhou") are a set of three. See the printed circuit board diagram for the connecting coils. T2 is the oscillating coil's mid-week model number is LF10-1 (red) , T3 is the first stage's mid-week model is TF10-1 (white), and T4 is the second stage's mid-week model is TF10- 2 (black). These three weeks in the week have been adjusted at the required frequency before leaving the factory. Only fine-tuning or even no adjustment is required after installation. Please do not make any adjustments. In addition to the shielding function, the middle-week casing also acts as a wire, so the casing must be reliably grounded in the middle week.

2) T5 is the input transformer, the primary mark on the coil frame is the primary, and the printed board also has the dot as the mark. The wiring diagram on the printed board can be clearly seen, do not install anti-reverse ( also Can be resolved with multimeter measurements).

3) V5, V6 are 9013 belong to the middle power transistor, please do not be confused with V1 ~ V4 is 9018 or 9014, belong to the high-frequency low-power triple tube, because their shape and pin arrangement are the same, V1 optional Transistors with low beta (such as green or yellow dots). V2 and V3 use triodes with medium beta values ​​​​(such as blue dots or purple dots), and V4 use triodes with high beta values ​​​​(such as purple dots or gray dots), otherwise the effect of loading out is not good, and the correspondence between the value of β and the color point : 40 to 55 times for yellow dots, 55 to 80 times for green dots, 80 to 120 times for blue dots, 120 to 180 times for purple dots, 180 to 270 times for gray dots, and 270 to 400 times for white dots. (Note that if the 9018 or 3DG201 triode is not marked, the color point can be used without distinction)

4) The nominal component parameters in the electrical schematic diagram are reference values. If there is an incompatibility with the actual given component parameters, please be flexible.

 

2. Installation process requirements:

Before hands-on welding, use a multimeter to measure the components, and be aware of them. Please install low-temperature and heat-resistant components (such as resistors) before installing, and then install larger components (such as In the middle of the week, transformers), and finally installed heat-sensitive components (such as tertiary tubes).

1) Resistor installation: Please select the resistance value of the resistor (refer to the schematic diagram of resistance calculation in this manual) and then bend the resistance pin according to the distance between the two holes. You can use the horizontal type close to the circuit board to install, or you can use the vertical installation. The height should be unified.

2) The lengths of the tiles of the ceramic capacitor and triode should be moderate, do not cut too short, and do not stay too long. They should not exceed the height of the middle week. Electrolytic capacitors are mounted vertically close to the circuit board, too high will affect the installation of the back cover.

3) The four wire leads of the magnetic coil (which is produced by the imported self-welding wire and can be used without the knife scraping or sandpaper sanding) can be directly plated with soldering iron and rosin solder wire several times and can be coated with tin automatically. Corresponding welds on the copper surface of the circuit board.

4) Since the dual dial for tuning is mounted very close to the circuit board, the upper part of the component pins in its periphery is cut with