Super-brain hacker

Chapter 88 Difficult to understand

When Lin Hong was almost finished eating, Cook began to talk about the topic and turned to amateur radio, attracting Lin Hong.

Feng Wan couldn't get a word in at this time.

And Xu Wenjing could still talk a few words at the beginning, but as the topic deepened, she could only sit next to her and stare like Feng Wan, looking at the two men in this big and one.

From the specific practices and improvements of ore machines, to the common types and styles of Yagi antennas, to the international competition between hams...

Lin Hong's mastery of radio technology was beyond Cook's expectation. He didn't expect that Lin Hong's long-standing achievements in the radio field were so profound at a young age. Lin Hong's many whims and improvements made him shout... You know, Cook's ham is more than ten years old, in their ham circle. His technical level is at the forefront. Today, he met a teenage ham in China, and his technical level seemed to be better than his, which had to shock him.

Cook and Lin Hong chatted more and more. When the chatted, Cook even asked the waiter to bring pen and paper, and the two drew on the paper.

The early hams were basically people with high IQ. High IQ is naturally more conceited, so soon, the discussion between the two gradually turned into a secret technical competition.

It is very pleasant to show your peers the technology you usually study and the new problems you find.

However, Lin Hong's superb technology gradually made Cook unable to fight, so Cook threw out some of the problems they usually encountered in their circle that were still stuck in the stage of argumentation. The most representative is how to better mix noise with noise today when there are more and more electromagnetic interference signals. The effective signal is separated.

This is not only a problem of the amateur radio industry, but also a problem of the entire radio industry. Major research institutions and governments around the world are making great efforts to study this technology. Obviously, this technology has been widely used in the military for a long time, but departments in various countries cherish it as highly confidential and have never been open to the people.

So hams can only be self-reliant and rely on their own strength to study. Although some results have been achieved in this regard, the effect is not so satisfactory.

Cook threw this question out, just to support the facade, indicating that he has studied it in depth in this area, which is already quite awesome.

He looked at Lin Hong with a proud face. The meaning was obvious. I have studied it to this point. How about you? Come out and have a look at the SHOW?

At this moment, Cook is not a college teacher at all, but a pure ham, like a competitive child.

Lin Hong looked at him with contempt, picked up the brush on the table and drew a circuit diagram on the white paper, and then pushed it over without saying a word.

Cook looked at him doubtfully, and then glanced at the circuit diagram.

What does it mean? A very simple signal separation circuit?

He stepped forward and looked at it again.

is a little interesting. A resonant circuit is added to the signal separation circuit.

Cook picked up the paper and put it in front of his eyes to watch carefully.

doesn't seem to be so simple. Although it is based on the separation circuit, a relatively large modification has been made. There is also a signal amplification circuit here.

Cook frowned.

Can this design work? No way, it seems that it will be destroyed less, right?

He frowned even more tightly.

It doesn't seem to burn out, and the feedback current just drops it.

This design is indeed ingenious, but why?

He looked at Lin Hong with a little surprise and looked at him carefully.

This circuit is only composed of a few most basic circuits, but when it is composed, the completed functions are completely different.

The whole part formed two other large circuits. Cook focused his mind on these two circuits. He simulated in his mind for a long time before he figured out that these two circuits were used to filter signals. One is to filter strong signals, and the other is to filter weak signals.

"Although this design is great, as far as I know, the filtering effect of these two large circuits is not very good? Strong signal and weak signal circuits will filter out effective signals at the same time. Cook raised his own objection.

"No." Lin Hong immediately replied confidently, "Have you noticed that there is also a noise generation circuit next to it?"

Cook quickly put his eyes back on the drawing. Sure enough, he saw a very hidden noise circuit in a corner. Its function is very simple, just generating noise, so the circuit is also very simple, which is equivalent to a harmonic generator, which can be done with two or three components.

Seeing this circuit, Cook didn't understand it.

Originally, I wanted to filter the noise, but now I have designed a noise circuit in it. Doesn't this make the background noise louder?

He looked at Lin Hong with a puzzled face.

Lin Hong seemed to expect that the other party would not understand.

He took out another piece of white paper from the table, then drew a horizontal line and a vertical line, divided the white paper into four parts, and wrote a word "black" in the upper left and lower right corners respectively, meaning black.

"If we look at this paper like this, we can clearly distinguish where it is black and where it is white, right?"

"Yes." Cook nodded..

Lin Hong turned the paper around, drew a few lines, divided the white paper into 16 small squares, and then painted one of them black every other square. After painting, he picked up the paper and said, "What about this? Is it going to be a little more difficult?"

Cook didn't understand what he meant and didn't answer.

Lin Hong was helpless, mainly because the conditions did not allow him to express himself, and the manual drawing was too slow. He suddenly saw Cook's suit, and his heart moved. He pointed to his gray suit and said, "Can your suit be seen as composed of black and white?"

"Yes." Cook nodded.. Although the suit looks gray, it is actually composed of two colors, black and white, but because of the fine black and white lattice, the eyes have this kind of visual deception.

"If we use black and white colors connected together to draw, the visual effect is very poor, but if we use the small dot matrix between black and white to draw, we can draw a very three-dimensional effect picture, and the picture can be clearer, and some details can also be expressed, isn't that right?"

Cook remembered the sketch and nodded involuntarily.

Lin Hong was relieved to see him nodding. In order to explain that this was really not easy, he continued to say:

"I found that this phenomenon also exists in the audio. The effect of the signal filtered by the strong and weak filter circuits does not seem to be very good, but by actively adding a little noise to it and introducing the specified amount of error, the most received signal effect will be better..."

After his explanation, Cook remembered a short story of World War II...Q