Thank you o0 for passing away with the wind0o, qtrqgm, Xiaoyao @ book lovers, warp speed for the reward, thank you for your vote!

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Since Lin Changming has now become the director of the car and wood factory, he usually has less and less time to go home, and he stays in the factory almost all day to study with those technicians how to improve old products and develop new products, and Lin Hong usually stays at the scrap yard.

It is said that it is a scrap acquisition station, but in fact it is no longer worthy of the name, Lao Xu Tou has no heart to take care of this acquisition station, he is not short of money, and he has the filial piety of his disciples and grandchildren. The reason why I put down this place is just to value this courtyard, and on the other hand, it is also to make my grandson and Lin Hongduo close.

Facts have proved that his decision is very correct, under the influence of Lin Hong, Sun Wu's academic performance is now in the middle and upper reaches of the class, and he couldn't even think of it before.

At present, the scrap collection station only occasionally collects some electronic and electrical waste things, and other things are basically gone, mainly Lin Hong is collecting, and most of them are unloaded by him after receiving them, becoming piles of components.

After Lin Hong finished practicing, he went to the car and wood factory, and saw that his father didn't have time to come back for dinner today, so he went directly to the scrap yard and got some food with Sun Wu.

Sun Wu was holding the Walkman given to him by Lin Hong in his hand and couldn't put it down, but he was distressed that he didn't have a tape at hand, so he could only use the radio function on it for the time being, but this is the countryside, and the listening effect is not very good.

After tossing and turning very boringly for a long time, he finally couldn't stand it anymore and said, "Uncle Xiao, I want to go back." ”

He has a lot of cassettes of pop songs at home, and he decided to go back and bring them all at once, anyway, it's not very far from his home, and he can do it in more than two hours back and forth.

Lin Hong, who was welding something with an electric soldering iron on the workbench, didn't reply, and said "um" directly.

Seeing this, Sun Wu shook his head a little helplessly: "Hongzi, I said that you make this thing all day long, are you tired?" ”

After saying that, he didn't stay any longer, and immediately took the Walkman and ran in the direction of home.

Lin Hong sat quietly on the workbench, soldering a small accessory in his hand, a small circuit board, only the size of a matchbox, but densely soldered with components such as resistors, capacitors, and chips. As can be seen from the newness of these parts above, these components are disassembled from different devices and then assembled together.

In front of the workbench, there is a pale yellow scratch paper, on which a pair of circuit diagrams are drawn with a ballpoint pen, the lines are straight and symmetrical, and the layout between the components is reasonable.

The matchbox-sized thing in Lin Hong's hand is the design schematic of a "adaptive signal filter", this drawing was finally finalized by Lin Hong after spending more than a month of continuous testing and debugging, as far as he knows, there is no similar product in China.

The reason why it takes so much effort to make such a thing is mainly because with the development of the economy, there are more and more factories around, and there are more and more interference signals in the air, which has a great impact on Lin Hong's amateur radio life.

Theoretically, all electronic devices are constantly emitting invisible electromagnetic waves, but they are large and small. Although these electromagnetic waves do not have a big impact on the lives of ordinary people, they bring great distress to the "ham".

The signal that used to be very clear to listen to is now becoming more and more blurred, often a lot of noise is mixed with useful signals, and it is not clear to listen directly to it, which puts forward higher requirements for hams, to filter those useless noises from the received signals, and receive the real signals transmitted by other hams.

The difficulty increase in this is not a little bit, but an exponential increase, which tests the technical ability of the ham very much. But over time, it often becomes boring and meaningless repetitive work.

In order to improve his receiving efficiency, Lin Hong designed this "adaptive signal filter", which is installed at the receiving end, and will automatically filter out invalid noise in a specific frequency range, which can greatly save the operator's time and energy.

After soldering the last component, Lin Hong took it to the receiving end of the amateur radio station next to the workbench, pulled out a cable socket at the receiving end, and then connected the small box in the middle, and installed it very simply.

The amateur radio station next to the workbench is placed on a wooden shelf about one meter high, with many grids in the middle, and there are many equipment in it, among which in the center is a black transceiver device, which is more beautiful and smaller than the one before Lao Xu Tou, with a blue LCD screen distributed on it, and several large circular knobs for frequency and amplitude modulation.

At both ends of the transceiver equipment, there are other strange small devices, which are basically some auxiliary tools, such as modified switching power supplies, power amplifier sets, power filters, transfer switches, voice callers, and electric key devices used to send Morse code.

These things filled the entire shelf with gusto, and eventually formed a very professional "amateur radio station".

This is the brainchild of Lin Hong's continuous efforts in the past three years.

There is a wooden door in front of the entire wooden shelf, usually when Lin Hong is not using the radio, he locks the wooden door with a bull's head lock, except for his closest people, outsiders don't know what is in it.

Of course, Sun Wu must have known, but without Lin Hong's permission, he would never touch these things. Although Sun Wu felt that these things were very awesome, they were too complicated to operate, and he was only obsessed with Lin Hong for a while in the early days of setting up the radio station, and then completely lost interest.

In Sun Wu's opinion, Lin Hong is a madman, guarding the front of this radio station day and night, constantly adjusting various knobs on it, in order to just have a brief call with others. Sometimes, after the two sides connect, they just inform each other of the call sign, and then disconnect and continue to look for the next target to communicate.

If you want him to stay in front of the radio like this for two hours, constantly listening to the disturbing noise, it would be better to kill him.

So, usually, Sun Wu was rarely here at night, and he preferred to hang out with the youths in the village to chat and fart, drink, go to the only dance hall in town to watch others dance, and even fight with others.

His parents are not here, and if it weren't for the old grandson who has been suppressing him here, it is estimated that he would have been lawless and had been in the police station a lot.

Lin Hong connected his newly made gadget, and as soon as he turned on the power, a clear call came from the speaker above the shelf:

"bg7xzz, this is a bg1vbb call, listening...... over。 ”

Seek demons