Difficulties and breakthroughs
——The A-group filter was successfully developed
Author: Fu Jikang
1. The technological gap behind diplomatic events
In 1972, President Nixon visited China, a historic event that marked the breaking of the ice in Sino-US relations.
However, for those of us who work in communications technology, there is one more thing that has brought us a huge shock. As soon as Nixon's plane landed, the accompanying staff opened the box and quickly set up a satellite communication circuit to transmit the television signal of President Nixon's visit to China back to the United States in real time through satellite, so that American viewers could watch this historical moment in real time. This technological miracle is due to the advanced satellite communication technology of the United States.
The power of satellite communications
The advent of satellite communication technology has completely changed the face of global communications. It makes long-distance communication faster and more reliable than ever, enabling instant information transfer wherever you are, as long as there is satellite coverage. The power of this technology was fully demonstrated during Nixon's visit to China, and it also made us communication technology workers aware of the huge gap in our technology.
The beginning of continental satellite communications
Faced with this technological gap, China acted quickly. Soon after Nixon's visit to China, China decided to introduce American satellite equipment and set up its own satellite ground station in Shahe. This ground station has become China's first attempt in the field of satellite communications, and also marks China's determination to step into the field of satellite communications. Although China had not yet mastered the core technology of satellite communication at that time, this decision undoubtedly laid the foundation for the development of China's satellite communication technology and started China's journey to catch up with the world's advanced level in the field of satellite communication.
Second, the challenge of being ordered in danger
Projects that no one cares about
After the start of operation of the satellite ground station, we did not order the A-group system in the process of communication with other countries, and when the other party requested to communicate with us through the A-group circuit, we were in an awkward position to be unable to implement the communication with other countries.
In the seventies of the last century, the mainland was still in its infancy in satellite communication technology, and the A-group filter as a part of the satellite communication equipment was a project that no one cared about.
Accept tasks and face doubts
For some time, I have been assigned by the Ministry of Posts and Telecommunications to work on communications projects in Xinjiang.
The Xinjiang Autonomous Region Posts and Telecommunications Administration attaches great importance to this telecommunications project. When my flight arrived at Urumqi Airport, the leaders of the management bureau were already waiting at the airport to greet me. After that, Ma Lihuan, the chief engineer of the management bureau, accompanied me to the Miquan receiving station and the Changji sending station to arrange the implementation of the communication project.
In accordance with the requirements of the Ministry of Posts and Telecommunications, I worked hard day and night with the comrades of the Xinjiang Bureau and brilliantly completed the task, for which I was awarded a second-class meritorious service.
In September 1977, when I returned to Beijing after completing my mission, Director Liu Zunsan was very happy to see me and said: You are back, come to my office.
When I arrived at his office, he asked me about my work in Xinjiang, and then the topic turned to the A-group circuits in satellite communications, and he said that there are no units engaged in manufacturing satellite communication equipment in China at present, and the relevant departments of the No. 4 Machinery Department and the Ministry of Posts and Telecommunications have contacted the relevant departments of the No. 4 Machinery Department and the Ministry of Posts and Telecommunications for the A-group equipment, and they have not yet engaged in research and manufacturing in this area. Now we can only do it on our own, and we have found some people, but they have not come down. Director Liu Zunsan introduced the situation. Then he said in an inquiring tone: Our satellite communications and the connection between various countries urgently need to solve the problem of group A equipment, can you accept this project that no one cares about?
Faced with this sudden question, I didn't know how to answer it for a while. It's an unfamiliar project, I don't know right now, what kind of problems I'm going to face and how to overcome them? I wonder if I'll be able to take on this task? But then I think about it, I have been engaged in communication technology for more than ten years, I have worked hard to learn all kinds of theoretical knowledge and participate in the research and development of various projects, each of which will experience a variety of new problems, face new challenges, bravely meet them, and overcome them, is the attitude I should have in life.
So, I accepted the assignment, even though I didn't know much about the project at this time.
After I accepted the assignment, I learned that an old engineer from the original unit had rejected the project. This made me the focus of everyone's attention, some of them were skeptical, some were ridiculed, and some were waiting to see my jokes. They thought I was too ambitious to challenge the old engineer.
It's true that my job title at the time was assistant technician, not even a technician, and it was natural to think that I was ambitious. But in Xinjiang, I didn't know anything about the old engineer, and even now, the goal of accepting this task was definitely not to challenge the old engineer. A misunderstanding plunged me into invisible pressure.
I didn't back down, I knew that their doubts, ridicule, speculations had nothing to do with me, and I would prove myself with my actions and prove that my choice was correct.
It was a difficult start, but I had no way back, only to move forward. I had to rise to the challenge, challenge myself, and challenge this project that no one cares about. I know it's going to be an uphill battle, but I believe that as long as I keep going, one day, I'll make it.
3. The dilemma of traditional design
Filter design challenges
After receiving this task, I began to understand the requirements of this project, which is simple to say, but also simple, this project does not have complex circuits. It's hard to say, it's really hard, the filters in the A group are very small, but the technical performance is surprisingly good. With such a small size, it is necessary to make such excellent performance before. I start
Realized that the project was destined to be a difficult one.
There are many different types of filters used in communication technology, but this time I encountered the requirements for filters, which were far beyond the scope of my experience. Achieving superior performance in such a small volume is undoubtedly a climb to the summit of Mount Everest for me.
Component sourcing challenges
Shi Yintang, a grassroots leader, was very concerned about my project and took the initiative to ask me what support I needed. I thought about it, thinking that the components designed in the project are non-standard, the supply of components will inevitably encounter difficulties, and if the components are not available, the work process will inevitably be affected. So I asked for someone to be in charge of the material supply. The two of us discussed it and felt that this work could be entrusted to Chen Shunhua. Chen Shunhua works in the component class, he is good at communicating with others, and he also knows more about components, he is responsible for this work, and should be able to do this job.
Indeed, in the process of design and test work later, Chen Shunhua traveled around to purchase the required non-standardized components. Every time you find an element, it's like finding a glimmer of light in the darkness, but then more darkness ensues.
Repeated failures in design and experimentation
To design the filter, I follow the traditional method, calculating step by step. At that time, the calculation was carried out using a hand-cranked computer, which was continuously shaken every day to calculate the value of each component. Then change the corresponding parameters, and shake out the value of the component, and so on.
These components were procured by Chen Shunhua. Then I install them, I test them. But the results were disappointing and repeated failures. Every time I failed, I felt pressured, but I didn't give up. I know that it is only possible to find a path to success if you keep trying.
I reflect on the formulas in my design, and some of the parameters in these formula calculations are set by myself. I'm tentative in setting these parameters. I didn't have any experience in designing filters before, every time I set the parameters, I can design a filter, I need to provide the components, install, test, if it goes well, the whole process takes a week, if there is any problem in the middle, a week is not enough.
Now I am tentatively setting these parameters, with a lot of blindness.
I decided to go out and ask for advice from experienced masters.
I found a master with more than 10 years of experience in filter making, he was very enthusiastic, he immediately calculated according to my requirements, and came to the conclusion that this filter needs at least 4 sections to achieve the required performance. However, if the filter requires at least 4 sections, it will be too large to fit in.
From this master's calculations, I once again realized the difficulty of A-group filter design. Maybe I'm really going to be a loser in this project, really ambitious.
Then I went to a university and asked a professor for advice. The professor was very happy to take me to a classroom, he explained to me the steps of calculation on the blackboard, he was very clear-minded, he was very proficient in formulas, I don't remember if he brought books, I remember him now, he didn't bring books, lecture notes. In short, I feel that he knows the design of the filter well, and I remember that he is very familiar with the melon, and he explains fluently, smoothly and skillfully.
When he finished speaking, I asked how the parameters of alpha ( ), bet (ß), and gamma ( ) in the formula are so certain. This question also stunned the professor at once. After all, professors focus on basic theories in school, and as for the practical application, it involves a wide range of questions, and it is difficult to answer them for a while.
Although I did not get a direct answer to the questions I raised, the professor's explanation was still very helpful to me. I have a clearer understanding of these parameters in the formula, which is the key to solving the problem in the future.
Back at work, I stopped my old calculations. I sat there next to the hand-cranked computer, and I didn't shake it anymore. I don't read the calculation formula in the book. I knew that even if I had to pull out another set of data, procure a bunch of components, and be busy for another week, I wouldn't have the luck to get the filter up to scratch. If this continues, it will only be a waste of manpower, financial resources, and material resources again and again, and repeated defeats.
At this time, a voice came: I can't do it, I fell into the pit now.
I know how many eyes are watching now, looking at the bustle.
Fourth, survive in a desperate situation
One night in a dream I successfully developed the A-group filter, I was very excited, and I was so happy that I woke up from the dream. Late at night I was still in the excitement, I thought about the dream, but I couldn't think of anything.
But I still try to think back to the dreams of the night, which make me comforted and happy, and make me see hope, and maybe one day, I will really see the light of success.
I remembered that Hua Luogeng once came to the Telegraph Building to introduce the optimization method, yes! The problem I am now encountering is also the question of how to optimize, and I am thinking about it again。。。。。。
I continued to think, from the professor's explanation, from the master's design, how can I find a breakthrough?
The master is a designer with more than 10 years of experience, and the method he learned must have been the method of the 60s. Now, more than a decade later, it is entirely possible that a new approach to design will emerge. Right! It's possible that a new approach will emerge. The key question is whether this method is the best area. I don't think it's the sweet spot. This makes me think a lot clearer.
In the 70s of the last century, it was common to see reports on the application of computer technology in newspapers and magazines, and computers at that time were mainly used in scientific research and computing, and if computers could be used to design filters, I believe that satisfactory results could be obtained.
However, for many people at the time, there was no opportunity to use a computer, and neither did I. We don't have a computer in our unit. I decided to go to the library and look it up.
I read books and papers, collected a lot of information on computer applications, and at once solved my loneliness and confusion. I focused on the application of computer in filter design, and these materials gave me a lot of inspiration, and I continued to experience and think from some cases and specific design methods described in these materials, and found methods and research results that could be used for reference. At that time, there were no photocopiers, and I carefully copied the valuable parts one by one, and I began to study how to borrow their results for my own use.
I continued to review, experience, and summarize.
Although I failed many times in the early stage, I also gained a deep understanding of the various parameters in the filter design, so when reading relevant books and papers, I was able to grasp the weight of their practical application, so that I finally succeeded in forming a set of design methods.
Since the parameters used in the design have been computer-optimized, the performance of the filter is also optimal when designed with this design method.
After many days and nights of hard work, I finally completed the design and production of the A-group filter. This filter is not only small in size, but also excellent in performance, which fully meets the technical requirements. I know that the success of this filter is not only a personal victory for me, but also a demonstration of China's progress in satellite communication technology.
5. Acceptance and approval of the chief engineer
The success of the A-group filter
Although I had achieved gratifying success, the surrounding environment was also a bit unexpected to me at this time, and my leader, a deputy director in charge of production, said in a disdainful tone: "What I measured doesn't count."
I was very puzzled at the time, the data I tested were all the results of the instrument test, why didn't my test count?
When the A-group filters were sent to the satellite ground station, I was anxious and waited for the final acceptance.
Wu Jincong, chief engineer of the ground station, personally carried out the acceptance. Wu Jincone is a model worker in Beijing, and he is very serious about acceptance. He first read my test report, and then pushed a test trolley, on which was an American instrument, next to an English technical manual, and the open page was the technical performance part of the A-group filter.
The test environment of the satellite ground station is good, the instrument accuracy is high, and Wu Jincone is the chief engineer of the satellite ground station, and the results of his personal test are authoritative.
I was just watching, and he was doing the testing himself. When he finished the test, he was surprised that the performance of the A-group filter I made was completely acceptable, and there was still a lot of margin compared to the description in the English manual. Wu Jincone signed the acceptance document with satisfaction.
At this moment, I am extremely happy, you must know that due to the good test environment of the satellite ground station and the high accuracy of the instrument, the test data here is better than what I measured!
The opening of the A-group circuit not only marks another step forward for the mainland in the field of satellite communications, but also means that the communication barriers between us and other countries in the world have been broken. This achievement made everyone happy. I have added confidence in my heart to believe in China's strength and potential in science and technology.
The A-group filter was successfully developed, and Shi Yintang, the director of the office, happily reported to Director Liu Zunsan, and the bureau leaders instructed to give rewards. In that year, I was named the advanced production worker of the year and received a bonus of three hundred yuan.
The news of the successful development of the A-group filter spread to other units, and some colleagues who made the filter were also very concerned, and they were eager to have the opportunity to communicate.
These units called, and at that time there was only one telephone in one unit, and the telephone was in the office of the unit leader. Whenever a foreign unit called to pay attention to the filter design, the deputy director of our unit politely refused because we had just made a filter and had no experience. I later learned about this situation, very puzzled, to know that the set of design methods I summarized are the best solution by computer calculation, not only to make the filter performance optimal, but also to design the work is simple, saving a lot of labor.
I was awarded a bonus of 30 yuan, which was a high reward at the time, and I wanted to buy some candy, dried fruits, etc., and share my success with my colleagues. However, I soon heard rumors that the success of the A-group filter was due to the production of the components by the comrades who made the components, and the chassis was made by the comrades of the metalworkers. When I heard this rumor, I thought to myself, since the prize money was given to me, it is only natural for me to accept it, and I don't think about other things anymore.
6. Achievements and prospects
Effect of A-group filters
The successful development of group A filters has greatly boosted the front-line staff of satellite communications, and the mainland can also use group A circuits to communicate with other countries in satellite communications.
This not only marks a small technological breakthrough in the field of satellite communications on the mainland, but also breaks down the mystery of satellite communication technology, encourages everyone to break the bottleneck in the field of satellite communications, and thus brings confidence to our development of satellite communications.
As a matter of fact, we have tremendous potential in science and technology, and the mainland's scientific and technological personnel are capable of solving problems.
Confidence and affirmation of potential
This success has made me deeply realize that as long as we have the courage to challenge, we can overcome any difficulties and achieve a technological leap.
This experience has taught me that challenges and difficulties are inevitable on the road of life. Some of these challenges come from the technology itself, and some from the surrounding environment.
For me, my career as a soldier has made me have the courage to fight, dare to fight, and be selfless and fearless in my bones. Years of experience in project research have made me develop a work style of respecting science, seeking truth from facts, and never giving up.
It is these challenges and difficulties that allow me to continue to grow and improve.
Only by bravely facing challenges can we continue to break through ourselves, contribute to the country, and make our lives colorful.