This time, Lin Hong seemed to have entered a mysterious state, unlike the previous muscle pain all over his body, this time he felt very comfortable.

Two hours passed quickly, Lin Hong regained his momentum, exhaled deeply, his mind was unprecedentedly clear, and he was refreshed.

He locked the door and trotted home to make breakfast.

Since it was a Sunday and he didn't have to go to school, he went back to the scrapyard after breakfast.

This time, he was holding a brown wooden box in the shape of a cuboid with several small circular holes in the box.

It was the "ore radio" that he has been working on lately.

In fact, his ore radio has been able to produce sound for a long time, but due to the problem of coil and ore sensitivity, it can only receive a local radio station in Tanglin City, and the sound is very unclear, and the noise is too heavy to be used normally.

However, Rao is like this, which really made Lin Hong excited for a long time.

The days that follow are a process of continuous improvement. For example, the components of the radio were scattered and there was no special box at all.

Later, Lin Hong went to the car and wood factory to play for a few days, and when everyone didn't pay attention during the break, he used the waste wood left in the factory to make such a long box by himself. After all, his father was an employee of the car and wood factory, and he often followed behind, so it was okay to simply make a box.

These days, Lin Hong also read a lot of information, he learned that in order to make the ore radio receive more stations, the sound has become clearer, first of all, you have to have a very good heaven and earth wire, and the Q value of the coil and variable capacitor is also the higher the better, in addition, the forward voltage drop of the geophone should also be relatively low, coupled with high sensitivity, the right impedance of the headset, its radio reception effect, even better than those professional radios.

The finished product he is holding in his hand at this moment is the only thing that has not been solved by him after his careful improvement these days, which is the heaven and earth wire, because to make a better antenna, it requires a relatively long metal wire and a huge space, plus Lin Hong saw in the book that although the antenna is simple, it is easy to attract lightning and lightning, which is very dangerous.

Therefore, in the case of uncertainty, Lin Hong did not make antennas without authorization for the time being.

When Lin Hong came to the scrap yard, Lao Xu Tou had not yet returned home.

He carefully observed the antenna made by Lao Xu Tou in the courtyard last time, and found that most of the materials used were iron wire, and there were a total of twelve wooden poles in the courtyard, which were divided in a corner of the courtyard in a rectangular shape, and several of them were erected outside the courtyard.

What makes Lin Hong feel strange is that the length of these wooden poles is not the same, but arranged in order from low to high, and the wires on the poles are interconnected with each other, forming a long strip of fishing net-like iron net, which is very spectacular.

Lin Hong doesn't have to guess to know that these antennas are not wound casually, they must be calculated through precise formulas, and every angle is exquisite.

There are a lot of books about antennas on Lao Xutou's bookshelf, but Lin Hong hasn't seen them yet. So, when he looks at the design of this antenna now, he doesn't understand it very well. It was a long time before Lin Hong knew what kind of antenna this kind of antenna was.

In the end, Lin Hong found a discharge tube and resistor at the end of the antenna, connected to the ground wire, he knew that this was Lao Xutou's lightning protection design, so that even if the lightning in the sky was drawn down, it could be said that the lightning could be smoothly introduced into the ground without damaging the equipment, and even at risk of being struck by lightning.

After some observation, Lin Hong came to Lao Xutou's room, he put the "ore radio" he made on the workbench, and then removed the antenna on the radio station, and finally connected it to his "mining machine".

Flipping the switch, the reed headphones on the lid of the wooden box make a "rustling" sound.

Originally, Lin Hong wanted to use the speaker from the radio to make headphones, but later found that the effect was not ideal, and finally found this model of Tian 737 reed headphones on a worn-out strange hat at the scrap yard, and found that the effect was good. Later, he also saw an article in the magazine dedicated to the headset suitable for mining machines, which introduced that the impedance of this headset is up to 750 ohms, which is just suitable for "mining machines".

Lin Hong constantly adjusted the position of the metal pointer on the ore, which was the geophone on the "mining machine", and the sound in the reed headphones began to change constantly, and the muffled voices of various radio stations gradually appeared.

"Sure enough."

Lin Hong smiled and nodded, after connecting to Lao Xutou's antenna, the listening effect was greatly enhanced, he had just adjusted it casually a few times, and he had already heard several radio stations, one of which was still the provincial capital, and it was very far away from here.

He continued to adjust carefully, and finally, the voice of the announcer of the "Central People's Radio" came from the headphones, and the sound quality was very good.

"Great!"

Lin Hong cheered, jumped up happily, clenched his right hand into his chest, and made a victory gesture.

This is an airwave from the capital of the capital, which is more than a thousand kilometers away. Most crucially, this is the radio station he listened to through the "ore radio" he made himself.

After Lin Hong's excitement, his emotions calmed down again, and he began to try to search for more radio stations, such as foreign radio stations and his favorite amateur radio stations.

The final result was frustrating, he couldn't receive foreign radio stations, even amateur radio stations, like Lao Xu Tou's radio station, and being able to listen to the radio station in the capital was already the limit of this mining machine.

In fact, he had expected such a result a long time ago, after all, this point had been clearly stated in the magazine a long time ago, but he still had some illusions in his heart.

"Ore radios still have certain limitations." Lin Hong recalled what he had learned, "Even if the antenna is good, the wavelength received is very limited, and it seems that if you want to collect a wider range of bands, you not only need to make a good antenna, but also improve other aspects." ”

The radio stations he receives now belong to long-wave radios, and the frequencies are generally relatively low, and if you want to receive higher-frequency bands, such as amateur radio signals, the ore machine can not meet the requirements at all, and only by replacing them with components with higher performance can it be possible to receive signals such as amateur radio bands.

However, in terms of finishing, Lin Hong is still quite satisfied. The ore radio has been successfully made for him, and in the process of production, some of the problems he encountered were basically solved by himself, and in the process of solving these problems, he also learned a lot of things, and put the theoretical knowledge in the book into practice, which feels very good.

Next, Lin Hong's plan is to make an antenna with better performance, so that at night, he can listen to the radio at home. In the process of reading books, he found that he would often encounter English words, after all, these technologies were first developed from abroad, whether it was books or magazines, many of the content was directly translated, and some basic terms were even written directly in English.

Therefore, Lin Hong's other plan is to learn English on his own. He found that in the evenings, some radio stations would broadcast some English teaching programs, so he decided that the important role after the ore radio was made was to listen to these English teaching programs. And when the performance goes up in the future, when you can directly listen to foreign radio stations, you will insist on listening to the original foreign radio programs.

When he went back to eat at noon, Lin Hong took the "mining machine" back by the way, and after eating, he came back to continue reading.

The book he read this time was related to antennas, and he checked some information and decided to make an "Yagi antenna" for emergency purposes for the time being.

"Yagi antenna" is also called "Yagi Uda antenna" is a directional antenna designed by Japanese antenna experts Yagi Shuji and Uda Taihao, with the advantages of high gain, strong directionality and simple structure, and it is quite convenient to make materials, which is very in line with Lin Hong's current conditions.

All afternoon, Lin Hong was reading a book called "Yagi Antenna Making Tutorial", which introduced in detail the basic principles and production methods of "Yagi Antenna".

And just as he was finishing the book, there was a sudden noise of talking in the courtyard outside, and it seemed that a lot of people had come.

Lin Hong put the book back in its place, walked outside to take a look, it turned out that it was Lao Xu Tou who came back, and he was not alone, there were a group of very bright faces, Lin Hong could be sure that these people were not from Heiyan Village or nearby villages, looking at their clothes, they looked like people from the city.