Development of productivity started in 1981

Chapter 34 Communications Research
1981年9月6日，农历8月9日
-
Early that morning, Wang Jiankun went to the morning market and bought some vegetables, meat and apples to treat his junior high school classmates.

At 7:, the junior high school students arrived at the gate of the yard.

When several people saw the sign that Liming Waste Recycling Station was recruiting, they fell into deep thought, wondering if they had come to the wrong place.

At this time, Wang Jiankun came out of the house and shouted, "This is it. You are in the right place. Come in."

Fang Guihua and five other students then came in.

Wang Jiankun explained that his family rented this house and since the place was so big, they planned to open a waste recycling station. They hired someone to collect the waste during the day, and Wang Jiankun would come here to sleep and watch over it at night.

Several classmates did not suspect anything, but they felt that his family was quite creative and actually wanted to open a waste recycling station in the county town.

After entering the house, everyone saw the black motorcycle parked inside. They excitedly ran over to look at it and touch it. Cheng Ming was anxious and asked if he could teach them how to ride it right away.

Wang Jiankun asked them who knew how to ride a bicycle, and said only those who knew how to ride a bicycle could ride it, otherwise they would definitely fall over.

Among the few people, only Fang Guihua and Cheng Ming can ride a bicycle. They learned it during the summer vacation and are not yet very skilled.

So Wang Jiankun taught Fang Guihua and Cheng Ming how to ride first, and Wang Jiankun said that he would take the other three for a ride later.

It is very easy to teach how to ride a Jialing 50 motorcycle. The main thing is to control the clutch and engage the gears. First, put the motorcycle in the yard, prop up the rear wheel and suspend it in the air. Then demonstrate how to start the motorcycle, how to control the clutch and engage and shift gears.

All of them were smart people. After being taught twice, they said they knew how to do it. Wang Jiankun asked five students to try pulling the clutch and shifting gears. After they had all learned it, Wang Jiankun asked Fang Guihua and Cheng Ming to ride in circles in the yard in first gear.

分别骑了10分钟左右再让他们试着升到2档和3档，再从3档往下降到1档。

After they had practiced enough, Wang Jiankun let them ride on Shuxiang Road and slowly accelerate. For safety reasons, he only let them shift to the 4th gear and control the speed within 50 kilometers per hour.

Then Wang Jiankun took Hu Chunming, Yu Min and Lang Junjian for two laps around the school's Shuxiang Road, Tianyou Road and Chaxiang Road respectively, and promised to teach them how to ride a motorcycle after they learned how to ride a bicycle.

It took several people more than three hours to practice driving. Wang Jiankun asked them to cook and eat together at noon and bought all the vegetables.

Fang Guihua volunteered to cook, and Wang Jiankun and four others helped him. They made fried pork with peppers, stir-fried beans, braised eggplant, tomato and egg soup, and a big pot of stewed rice.

When everyone was able to eat, although each dish was very large, they all finished it and soaked up the soup with rice.

Several people worked together to draw well water to wash dishes and pots. After cleaning up, they said goodbye to five classmates and returned to school for lunch break.

Wang Jiankun told them that they could come over to play on Sundays if they were free, and if not, they could buy some vegetables and cook to improve their meals.

After spending a few days with them, I learned that these students would go back to the dormitory and eat the pickled plums and pickles they brought from home with their meals.

High school is different from junior high school. Although you live on campus in junior high school, you can go home every week. Generally, you can bring some fresh vegetables that are not easy to spoil in the first two or three days. But this is not the case in high school. You can only bring pickled mustard greens and pickles, which will not spoil for several months.

After a short lunch break at noon, Wang Jiankun rode his bike to the supply and marketing cooperative to buy a soldering iron, rosin, tin blocks, capacitors, resistors and other things. He was going to start making a shortwave radio.

Although he could use his super powers to synthesize directly according to the simulated optimized drawings given by Zhizi, in order to exercise his hands-on ability and prevent being exposed in the future, he decided to do most of the processes manually, and some parts could be modified with super powers.

The frequency range of shortwave is 1.6 MHz to 30 MHz.

Wang Jiankun decided to make a radio with a wave band of 25 meters that could receive frequencies of 11.60-12.10 MHz.

This band has the most radio stations, and the reception is best in the morning, noon, evening and before midnight, with little noise.

There is no interference where Wang Jiankun is, and the house is not made of steel bars, so there is no need for an outdoor antenna.

One of the most important components of a shortwave radio is the high-frequency transformer. After asking at the supply and marketing cooperative but failing to find one, Wang Jiankun asked Chieko to help search for information in his mind and found the document "Principles and Analysis of High-Frequency Circuits".

Since there was no real object, Wang Jiankun had to ask Zhizi to design one based on the schematic diagram, making sure it was as suitable as possible for the design of the time, and then he used his super powers to synthesize one.

Without a multimeter, Wang Jiankun went to the only electrical repair shop in the county, used his superpowers to project into his mind and then used his superpowers to copy one.

Wang Jiankun tested all the purchased parts one by one and used his super powers to repair the defective or broken ones so that all parts could perform at their best.

Since he had already bought a radio, Wang Jiankun decided to refer to the appearance and some of the circuits of this radio which could only receive medium and long waves.

Ask Zhizi to help with the design, and then ask him to explain the basic principles of each part of the circuit and what its function is.

Wang Jiankun also used his superpowers to draw blueprints, write down the design ideas and improvements that made this radio able to receive shortwave waves.

After all these were done, Wang Jiankun started to solder the components. Of course, the circuit board was also synthesized using super powers. Although it was not difficult to manufacture, it involved a lot of equipment and chemical reagents, so it was better to synthesize it faster.

Insert the pins of the components into the holes in order from small to large and from low to high, and solder them one by one with a soldering iron.

Since it was my first time operating this, I took a lot of detours and parts were damaged many times.

But since it has superpowers that allow it to be repaired, you can practice it without worry. At most it will consume some electricity and rosin, and the other parts and tin can be recycled.

Almost four hours had passed before Wang Jiankun finally learned to operate the soldering iron skillfully and solder evenly.

Wang Jiankun looked at the time. It was almost half past five. He had to go eat and then prepare for evening self-study.

So I packed up my things and put them in the drawer, sorted out the more than 20 kilograms of scrap iron, several kilograms of scrap copper and more than 20 kilograms of waste paper that I collected today, recorded them in the account book, locked the door, and set off for school.

I passed by the school's message room and went in to check and found my own telegram. It was sent by my father at noon. There were a few words on it, which roughly meant that I had learned to drive from my friend Cheng Xing yesterday, had started driving this morning, and would drive back to pick up goods tomorrow morning. I was going to meet Wang Jiankun during the morning break.

I put away the telegram and went to the cafeteria to eat. I ordered 6 taels of rice and bought a steamed chicken shell as a dish.

Wang Jiankun found that this dish was quite affordable, costing 3 cents per serving. The upper part of the small bowl was the chicken shell (the chicken skeleton left after the chicken legs, breast and other meat were taken away, called "chicken shell" in Wuyuan), and the lower part was beans, peppers and eggplants.

A serving of steamed chicken shells with rice flour contains vegetables, meat, and oil, both vegetarian and non-vegetarian. It tastes pretty good. Wang Jiankun has made this dish twice.

After eating, I washed the lunch box and chopsticks and walked towards the classroom.

Before evening self-study, Yu Zirun suddenly asked Wang Jiankun whether he had ridden a motorcycle to the supply and marketing cooperative today.

Wang Jiankun didn't intend to hide it from his classmates, but he didn't want to make a big fuss about it either, so he whispered, "Yeah, where did you see it? Don't tell anyone!"

"I was in the supply and marketing cooperative when I saw you hurriedly riding away on a black motorcycle after buying things. What does your family do? Why did they buy you a motorcycle?"

"I was a farmer in my hometown. I started doing some small business during the summer vacation, and by chance I bought a motorcycle."

Yu Zirun's eyes showed a look of disbelief, he pouted his lips and stopped talking.

During evening study, Wang Jiankun began to imagine more uses for radio. Since he could use radio to listen to the broadcast, he could make a simple radio device that could be used for conversation or just sending and receiving information.

Wang Jiankun began to envision the composition of this device or communication system.

First, each communication terminal must transmit information via radio waves.

Because the most that wired services are available are similar to current telephones. The difficulty with current telephones is the high cost, and we do not have the ability to mobilize so many resources.

For wireless, you only need to build a few relay stations and manufacture terminals as needed. The terminals can be used within the coverage of the relay stations. The choice of frequency should be carefully considered. It is not appropriate to use shortwave, which may easily be suspected of being a spy device. Use medium or long waves. In the early stage, it is mainly to meet the needs of contacting family members and partners. Terminals and relay stations can be used less.

After listing the requirements, Wang Jiankun asked Zhizi to help him search for information in his mind to see if there was any technology that could meet these requirements.

I read in an English magazine that the American company Motorola has already built wireless paging systems in many countries.

The system is to build information sending base stations in the city, and then sell receiving terminals. The base stations are connected to the wired telephone system.

When you want to find someone, you can call the paging station and tell the staff which number to call, and then let the paging station send a short text and digital message to the terminal held by the person you want to find.

In this way, when the message is sent and received, the terminal will display the corresponding information. The person receiving the message can then find a nearby landline to call back, or act according to the received information.

What Wang Jiankun wanted was a terminal that could both receive and send messages without relying on a fixed telephone system.

According to the description in your mind, first roughly draw on paper the working mode of the entire system and the general appearance of the terminal.

The power of the base station should be controlled at 100 watts. There are two types of radio wave coverage: one is for communication between base stations, which is controlled at 150-200 kilometers and is used for relay transmission of signals; the other is for communication between base stations and terminals, which is controlled at 20 kilometers.
The terminal's function is currently only to send and receive text messages, so it is called a text transmission receiver, or text machine for short, and it does not make audio calls.

The text machine was designed with the help of Tomoko, based on the appearance of a radio and pager. It had a black and white screen at the top that could display two lines of a total of 16 words or symbols, and a keyboard at the bottom.

Wang Jiankun envisions that pinyin input can be converted into Chinese, and punctuation marks, numbers or just letters can also be input.

There is a retractable antenna on the back, which can be pulled out when sending or receiving information. If it is not pulled out, it can only receive the enhanced signal sent by the base station, and can receive prompts that there is information to be transmitted.

Each text machine will have a fixed number, and after editing the message, you can choose to send it to a specific number.

Terminals within the coverage of the same base station only need to pass through one base station to relay information, while information between different base stations requires two or more base stations to relay transmission.

Wang Jiankun's idea was designed entirely based on his own needs, and he was unaware that many of the technologies involved had already been researched and applied or were being researched by foreign communications giants such as Motorola and Ericsson.

For example, the text machine he envisioned was very similar to a mobile phone. For the sake of simplicity, it was temporarily designed to send and receive text messages. If more functions were added, it would be able to make calls.

The three evening self-study sessions passed in Wang Jiankun's wild imagination.

Seeing how engrossed he was, his deskmate Yu Zirun got a little angry as he didn't respond when he called him. Fang Guihua also called him to go to the bathroom but he didn't go as he didn't want his train of thought to be interrupted.

After evening self-study, Wang Jiankun waited for a while before walking out of the school gate. At the gate, he met Yu Zirun’s father who came to pick her up.

Wang Jiankun thought that her father really loved his daughter and came to pick her up almost every night.

Yu Mingde, who came to pick up his daughter, knew Wang Jiankun somewhat, because Wang Jiankun was his daughter's deskmate and, according to his daughter, his daughter's admission score was the highest in the class.

So every time I meet him, I would say hello to him, and at the same time, I would ask my daughter to get along well with Wang Jiankun and ask him for help with some study problems.

Yu Zirun was a little confused about his father's request, but he was still relatively friendly to Wang Jiankun, although this classmate sometimes behaved a little strangely, such as when he ignored him when he tried to talk to him tonight.

On the way back, Yu Mingde noticed that his daughter's attitude towards Wang Jiankun was a little bad tonight, so he asked: "Why did your expression look a little strange after seeing Wang Jiankun tonight? Did he offend you?"

"I went to him to ask a question tonight, but he ignored me."

"Oh, why did this kid treat you like this?"

"He said he had something very important to do. I didn't know what he was busy with. He was writing and drawing on a notebook. I couldn't understand things like analog signals, digital signals, attenuation and enhancement, error correction, etc."

"Oh, is he doing research? He is only in the first year of high school, how can he learn all this? This should be university communication knowledge."

"I don't know. He's a bit weird. He listens carefully in some science classes but never takes notes. He doesn't listen carefully in many arts classes. He just stares blankly and I don't know what he's thinking."

"It seems that your deskmate has made plans for his future. You can learn some good study methods from him, but don't learn the bad aspects. He may have good talent and a good memory, but you can't. A good memory is not as good as a bad pen."

"I won't learn from him. Let's see how he scores in the next monthly exam." Yu Zirun said proudly.

The father and daughter chatted along the way, and Yu Mingde became more and more interested in Wang Jiankun.

I learned from my daughter that this boy was from a production team far away from the county town. I don’t know what business he did during the summer vacation to get a motorcycle.

During his school years, he had a clear goal of preparing to take science exams, and he should also be doing research in communications. I can talk to him about it if I get a chance.

My daughter came here to study with me, and she doesn’t have many friends. It’s nice to meet a classmate who has good grades, clear goals and is quite capable.

At school, she could ask him to help improve her daughter's grades. Although she graduated from a technical secondary school, she is no longer able to tutor her daughter.

Wang Jiankun didn't know that the father and daughter were discussing him, and some of his secrets were known to others, but these superficial things didn't matter. As long as he disguised himself well and no one was investigating him specifically, the secret would not be exposed.

After arriving home, Wang Jiankun did not go to bed immediately. Instead, he decided to make a shortwave radio tonight and try it out to see what effect his handmade radio could achieve.

It is quieter at night, which is suitable for doing delicate work.

Wang Jiankun fixed the components one by one on the circuit board. After welding, he installed the battery and tested it. The indicator light lit up normally.

The next step is to insert the handmade earphones into the connection hole and connect the telescopic antenna and stretch it out.

Take the radio into the yard and point the antenna toward the starry night sky.

Slowly turning the FM switch, after a while, the crackling sound turned into human voices. After listening for a while, Wang Jiankun found that it was Japanese. He didn't understand it, so he continued to turn the switch, and then English appeared.

After listening carefully for a while, I found that it was the ABC news channel broadcasting the news, and the news was talking about personal computers.

It is said that a company called IBM launched a personal computer last month that runs on the Intel 8080 information processor. IBM calls it the 5150 computer and it runs on MS-DOS.

Wang Jiankun seemed to understand what was said, but he only knew that this was a small device for processing information.

When I heard that it is a device that can process information, I thought that my base station must also process information. Then the design principle of this device should serve as a reference for the design of my own base station. I need to find more information in this area.

Wang Jiankun continued listening and found that the song started playing after the news broadcast, so Wang Jiankun had to adjust the switch again.

At this time, a Russian channel came out. Wang Jiankun didn't understand it, so he changed the channel again and heard the BBC news.

Wang Jiankun listened carefully for a while and found that it was talking about the Soviet military exercises.

The BBC host said that the exercise started two days ago and it was large-scale, with various advanced preparations unveiled one after another.

The Soviet Union's steel torrent rolled across the plains of Western Europe, and Western European countries trembled in fear of the outbreak of World War III.

Wang Jiankun spent the whole night listening to the news, mainly English news, as he couldn't understand news in other languages.

He carefully noted down the start and end times of the program as told by the host, and planned to spend some time in the evenings listening to the news to learn about major events happening in the world and some cutting-edge scientific achievements.

(End of this chapter)