Siheyuan starts from the stationmaster

Chapter 153
After thinking for a while, Bai Zirui came to the Department of Radio Electronics of Yanjing University, found Xu Chenghe, the director of the department, and said directly: "Director Xu, hello! I am Bai Zirui, majoring in national economics in the Department of Economics. Students from the Department of Electronics, please help me assemble the stereo radio."

Xu Chenghe said with a smile: "Student Bai Zirui, I know that you are a student of Mr. Dai, the first champion in the college entrance examination after the resumption of the college entrance examination in Beijing. I heard that you have recently taken leave to start a fast food business. Mr. Dai and other students from the Department of Economics Several professors also bring students to you for hands-on activities.”

Bai Zirui told the truth: "Director Xu, my fast food business is already on the right track, so I went south to Yangcheng to buy goods and started trading these few days."

Xu Chenghe glanced at him quite unexpectedly and said: "You can just do your business and resell. Why do you want to assemble radios?"

Bai Zirui took it for granted: "Of course I do business to earn money and sell things. Now, getting married requires four major items: 'three turns and one ring', and one of the rings is the radio. The most profitable selling radio is naturally the stereo radio. , that’s why I want to ask the students from the Department of Wireless Electronics to help assemble the stereo radio.”

Xu Chenghe said: "Student Bai Zirui, you are quite honest, but students should race against time to study so that they can build the country's electronics industry after graduation, instead of being distracted by other insignificant things."

Bai Zirui retorted: "Director Xu's words are wrong. Students in the Department of Wireless Electronics always learn the knowledge in textbooks at school. Now that the country is in a state of waste, it is difficult to allocate funds for the Department of Electronics to build a laboratory.

In this way, wouldn’t the students only talk on paper in class, lack practical hands-on skills, and have no access to the latest cutting-edge technologies in the world, so that after graduation, the students will only be a boastful nerd. Contribute to the construction of the industry? "

Xu Chenghe was enlightened by Bai Zirui's words, and he said solemnly: "Student Bai Zirui, I asked the students from the Department of Wireless Electronics to help you assemble a stereo radio. Your business will grow in the future, can you help us?" Get the latest technology in foreign electronics?"

Bai Zirui said solemnly: "Director Xu, don't worry! Now that the country has reformed and opened to the outside world, when I can get a business license after a while, I will set up a company and go to Xiangjiang to develop. I will definitely help the Department of Wireless Electronics to obtain the latest foreign technologies and materials. .

Students help me assemble stereo radios, and I will donate 20% of the revenue from the radio business to the Department of Wireless Electronics to set up a laboratory and set up scholarships to help students improve their lives. "

Xu Chenghe said ecstatically: "Okay! Then I will arrange for the professor to lead the students to help you assemble the stereo radio."

After he finished speaking, he took Bai Zirui to find a professor in the Department of Wireless Electronics named Xiang Haige, and told him that Bai Zirui asked his classmates to help him assemble the stereo radio, which aroused Professor Xiang Haige's strong interest.

Because he recently encountered the problem of radio frequency in overcoming wireless communication, and the working principle of FM stereo radio: the high-frequency signal received by the antenna passes through the input circuit and the local oscillation frequency of the radio (its frequency is higher than the external high-frequency signal by a fixed intermediate frequency) , China's intermediate frequency standard is 465KHZ) together into the frequency conversion tube for mixing - frequency conversion.

The load circuit (frequency selection) of the frequency conversion stage generates a new frequency, that is, the intermediate frequency generated by the difference frequency. The intermediate frequency only changes the carrier frequency, and the original audio envelope does not change. The intermediate frequency signal can be better amplified. The signal is detected and high frequency signals are filtered out.After low-amplification and power amplification, the speaker is pushed to produce sound.

This involves the frequency of the radio, which is helpful for his research. Professor Xiang Haige immediately agreed, and immediately led two proud students with tools to follow Bai Zirui to the house he rented in Zhongguancun.

Professor Xiang Haige saw the electronic components that Bai Zirui bought from Yangcheng, ready to assemble the FM stereo radio. He stepped forward to check these components. These components are basically inferior products from the radio factory. , there are more than a dozen regular products mixed in it.

Xiang Haige knew that these were the components that the workers of the radio factory brought out from the factory, and used these components to exchange some money and tickets to supplement their household expenses. Now many workers do this. No one in the factory went back to investigate.

Professor Xiang Haige is no stranger to FM stereo radios. He demonstrated to students that he had dismantled several sets in class. After checking the quality of these electronic components, he prepared to assemble the radio with two students.

Bai Zirui saw that Xiang Haige and two students were preparing to assemble the radio, and he tentatively asked, "Professor Xiang, the FM stereo radio I want to assemble is a 9600-band radio like the Sanyo SANYO-MR-4 radio."

Xiang Haige frowned when he heard that Bai Zirui was going to assemble a 4-band FM stereo radio. In fact, in 1975, Modu made the first [-]-band radio in Chinese history, and won the National Technology Award for two consecutive years. Prizes.

But that radio used integrated circuits, and Huaxia's output of integrated circuits was still very low at this time, so other manufacturers wanted to follow suit, but they often had to give up because they couldn't get key components.

This is also impossible. Huaxia's electronic technology has lagged far behind the West, especially in large-scale integrated circuits. There are really not many technicians who can figure out the principles except for scientific research institutes, and these technicians are often Concentrated in several big cities such as Beijing and Shanghai, this makes it difficult for ordinary radio factories to develop new products.

Xiang Haige had visited a certain scientific research institute in the capital, so he naturally knew that the principle of the 4-band FM stereo radio involved the integrated circuit, so he pondered for a while and said: "Student Bai Zirui, the [-]-band FM stereo radio involves the integrated circuit. , if it is assembled, the price may not be acceptable to ordinary people."

Bai Zirui smiled and said: "Professor Xiang, you are an expert in radio technology. As a professional, you must know better than me. I have assembled and repaired radios before, and I suddenly thought that we would make the circuit in it like this. design……"

According to the circuit diagrams seen by later generations, he introduced the detailed plan of integrated circuit allocation reduction and optimization to Xiang Haige, and drew the circuit diagrams casually.

Listening to Bai Zirui's explanation, Xiang Haige suddenly understood, and when he saw the circuit diagram he drew, his eyes lit up even more.He sincerely praised: "This design is really ingenious. How did you come up with this design, Bai Zirui?"

Bai Zirui said with a guilty conscience: "Professor Xiang, this is just my immature idea. I'm just talking on paper. Whether it will work or not depends on your practice."

Xiang Haige nodded and said: "It will definitely work. Let's assemble a radio according to this design idea and try it out." After he finished speaking, he led the two students to start working.

　Thanks to: Xiaoer came to the pot of wine, Shelley lived a wonderful life, the night breeze was so cool, 豮艸芔猻立, 20190501090333925 and other book friends voted for support.

　　


(End of this chapter)