"Super... Ultra-shortwave what?"

Yao Ziqiang circled around the iron box twice and asked curiously

"Ultra-shortwave radio!"

Li Fan patted the iron box with a sigh

"As long as you put up an antenna, you can send telegrams to each other thousands of miles away. Pen %Fun %Pavilion www.biquge.info"

Then he spun around twice in annoyance and patted his head

"I was so sluggish, I just thought that there were no diodes, no transistors, no this, no that, but I didn't expect that the first generation of radio stations didn't use these in the first place!

It's not too late, though, and the spark level isn't too difficult, so I should be able to figure it out by now.

Old Yao, let Thor come over!"

After finishing speaking, he found that Yao Ziqiang was standing motionless with his mouth open.

Li Fan approached him a little strangely

"Old Yao, old Yao, what's wrong with you?"

Yao Ziqiang's body shook violently, and he grabbed Li Fan's clothes in disbelief and asked in a whisper

"Ancestor, this is the one you said can speak from afar?"

Li Fan was stunned

"I was talking about mobile phones before, which are more advanced than this, this... I can talk, but it's not the kind of thing we usually say.

You need to learn specially, so let's pick two clever little girls and I'll teach them Morse code.

And don't forget to call Thor!"

Yao Ziqiang took the order and left, and Li Fan began to draw resonant circuits on paper.

The resonant circuit is simply a simple harmonic vibration of physics, where the acceleration of an object is proportional to the displacement away from the equilibrium position, and always points to the vibration under the action of the restoring force in the equilibrium position.

It's very simple, but if it's used as a transmitter, it needs a very powerful battery, and because there are no transistors, he also needs a bulky antenna.

Li Fan thought for a moment and said to the dog who was making a lot of noise next to him

"Dog, can my brother tell you something?"

The dog's mechanical eyes turned

"Big brother, except for borrowing money, everything else is easy to say!"

Li Fan".......... Why am I borrowing money from you, do you have any money? Hurry up, lend me one of your solar panels. ”

"Boss, the battery board is my lifeline! Just like your balls! If someone asks you to borrow a ball, will you borrow it?"

Li Fan said impatiently

"If I'm like you, I have a dozen balls, and a lot of folded spare balls, I'll borrow them!"

Goudan opened his warehouse aggrievedly, simulated the sound of sobbing, and slowly handed Li Fan a battery board.

Finally calming the dog, Thor and Yao Ziqiang pushed open the door and walked in

"Village Chief, are you looking for me?"

Li Fan pulled the two of them to sit down and asked solemnly

"Old Thor, can you wire the metal?"

Old Thor asked cautiously

"I don't know how fine you want to pull?"

Li Fan used a quill pen to draw a straight line on the paper

"It's about that thickness. ”

Old Thor stared at the thin line for a moment, then closed his eyes and began to think, and after a while he nodded slowly

"Yes!"

That night, after Li Fan set up the radio station in Yang Village, he taught Yao Ziqiang how to operate it simply, and hurried to the transformation base with materials and dog eggs.

Because of the frequent traffic between the sheep village and the reconstruction base, there has been an extra dirt road that has been compacted very strongly.

Li Fan looked at the surrounding environment, it was afternoon, it was not very dim, if it was night, it was dark here, and it was estimated that he would not see anything.

When the glass is ready, let's add street lamps here.

Rao is road is much easier, and it will be almost two days after Li Fan arrives at the base.

I couldn't take a break, so I casually greeted Liu Han, who was full of surprises, and got two thicker logs from the warehouse, and asked Liu Han to lead someone to erect them.

Then the antenna made of precious iron resources was carefully tied and fixed, Li Fan ran to the office below and bared his teeth at the dog.

Goudan once again "miserable" pulled out a battery board, covered his eyes with a mechanical arm, and then handed it to Li Fan.

Li Fan connected the battery board, and after fiddling with it for a while, he solemnly issued a secret signal - three long beeps.

It seemed like only a second, and it seemed like a century.

The metal paddle connected to the circuit suddenly shook twice, and a beautiful three short beeps came from the simple resonant headphones.

Li Fan slammed his fist on the table and roared excitedly.

Liu Hanxia, Xia Xiaohua and others looked at each other, and Xia Xiaohua asked boldly

"Teacher... You.. What are you doing?"

Li Fan turned around and pointed to the spark transmitter behind him and asked

"Xiaohua-san, do you know this?"

Xia Xiaohua glanced at it twice and said in wonder

"High School Physics Volume II, Resonant Circuits. ”

Li Fan nodded

"That's right, it's a resonant circuit, you have basically learned the above principles, do you think that what you have learned before seems to be out of reality, and it is difficult to have an effect in real life?"

Although Xia Xiaohua didn't want to say this, she still nodded in embarrassment

"Well, teacher, I think math is indeed very useful, but Chinese physics and chemistry... It doesn't seem to work. ”

Li Fan clenched his fists and said in a deep voice

"Xiaohua, the teacher will teach you an important lesson today, why physics can change the world!

Remember how we learned about generators?"

Xia Xiaohua nodded and replied quickly

"Cutting magnetic inductance lines, as described in the above experiment, any change in the magnetic field can produce an electric field in the conductor!"

Li Fan smiled

"That's right, it's useless to just master these things, the following is the key!

The battery generates an electric current inside the first wire.

The moving electrons create a magnetic field around the wire.

The magnetic field extends out to reach the second wire.

When the magnetic field in the first wire changes, the electrons in the second wire start flowing.

Then we can do one thing, and that is to create a continuously changing current in the conductor by means of a continuous closing switch.

If the current is large enough, and the antenna is amplified, will the same thing change at a distance?

What does that mean?"

Xia Xiaohua's brain turned very fast, but after thinking for a while, she stood in place with a shocked face, and she couldn't understand a word.

Liu Han jumped to his feet in a hurry and asked hurriedly

"Eve, what the hell is going on, what are you saying?"

Xia Xiaohua turned her face and swallowed a mouthful of saliva, her face still carrying an indescribable shock and a kind of piety and surprise to open the door and see Xintiandi

"Uncle Liu... This means that as long as we develop a signal that both sides understand, we can communicate with Yangcun from afar....... To put it simply...... There is no distance between us!"

Liu Han scratched his head in distress and said angrily

"To put it simply, I don't understand!"

Xia Xiaohua looked at Liu Han helplessly, and after thinking about it, she finally found a way that Liu Han could understand

"Uncle Liu, for example, now Village Chief Yao of Yangcun Village also has this thing in his hand, so what do we say, Village Chief Yao will know immediately!

On the contrary, what Village Chief Yao says, we will know immediately here!"

Liu Han understood, and it was precisely because he understood him that he was so surprised

"You mean... We've all become tailwinds?"

"That's right, from now on, we have a tailwind!"