By linking my account to the check-in system, I became a leisurely traveler.

Chapter 210 Music in the Wilderness [Second Update!]

Snow stopped.

A layer of snow had accumulated between the tree branches and on the ground, making a crunching sound when stepped on. The distant mountains were covered in snow, blending into the color of the sky. Despite the heavy snowfall, it wasn't as cold as I had imagined, and the distant lake hadn't frozen over yet.

Today, Li Younan can finally go out to find suitable wood to make a crystal radio for himself.

To be honest, it's quite exciting to think about. This step doesn't take too long. He went into the forest, found a piece of spruce of a suitable size, chopped it into a log, and took it back to process.

To hear a crystal radio with sufficiently clear sound, every step must be done to the best of one's ability, using whatever resources are available.

The first thing is the antenna.

The roll of copper wire that Li Younan got from the production team was mainly used to build an antenna.

He first built a wooden frame, then twisted copper wire into a Yagi antenna and set it up directly outside the house.

To be fair, it is the wilderness after all, which has disadvantages for making crystal radios, such as being far away from signal towers. But it also has a great advantage – there is almost no interference from outdoor electromagnetic waves, unlike the electromagnetic environment in the civilized world.

He set up the Yagi antenna, with the other end of the copper wire extending directly into the room.

During this process, Li Younan, of course, did not forget to turn on video recording.

He excitedly told the camera, "Hey guys, today we're going to make something really fun. Remember when I asked the crew for a roll of copper wire at the beginning?"

"I've now turned it into an antenna. Yes, today we're going to build a doomsday artifact—a radio that doesn't need electricity. Some people might ask, can a radio work without electricity? You'll understand once I've finished making it."

"First of all, this is an antenna, and the function of an antenna is, of course, to receive signals."

"But the problem now is that we can't hear any of the signals the antenna receives. On the one hand, the antenna's signal is too mixed; it can receive AM broadcasts at various frequencies... maybe even radio programs? Who knows..."

"On the other hand, the antenna signal is too weak. How do we solve these problems? That's where a resonant circuit comes in."

While explaining, Li Younan worked. He found a piece of wood, whittled it into a perfect cylindrical shape, and then wound it around the copper core wire from the hand-cranked generator.

"This thing is called an inductor. How do we measure the magnitude of inductance? With all parameters being equal, the more turns the coil has, the greater the inductance. So what is the function of an inductor? The main function of an inductor is to generate an electric field when a passing AC signal is detected..."

Li Younan patiently explained the principles and steps of making a crystal radio to the viewers off-camera.

He knew, of course, that the production team would most likely cut out all of his explanations when the show aired—after all, most viewers didn't have enough knowledge to understand them.

But Li Younan still explained very carefully, without any perfunctory attitude.

The reason he did this was partly because he was bored during production and had to say something, but another reason was that he hoped to use the broadcast of this program to influence some children who love science, especially teenagers in China, and to inspire their interest in science and technology.

If you plant a seed now, it might sprout into a towering tree.

With copper wire, all other raw materials for making a crystal radio can theoretically be found in the wilderness.

The only difficulty is in hand-stitching copper core wire in the wilderness, but it's not entirely impossible.

In some wilderness areas, if you find green stones, they are very likely to contain copper ore—copper oxide is green.

The copper can also be extracted through smelting, but it would be extremely difficult to make a mineral radio from this crude copper.

Li Younan said to the audience off-camera: "People who frequently experience the end of the world know that when all communication is paralyzed, you must hold firm to one belief—you are definitely not the only survivor."

"Therefore, it becomes especially important to stay in touch with the outside world, and a crystal radio is something you can rely on when the end of the world comes and there are no communication devices."

"People can find better and more convenient materials in the city..."

While assembling the crystal radio, Li Younan used his woodworking skills to create a flat frame control panel for the radio.

The core components mainly include detectors, tuning capacitors, and ground and earth cables.

The antenna and ground wire were already taken care of, and as for the detector... Li Younan simply removed the diode from the hand-cranked generator.

It must be said that the parts inside this hand-cranked generator are perfectly compatible with the core components required for a crystal radio.

A hand-cranked generator is not just a motor with enameled copper wire and a magnet. In modern society, when using a hand-cranked generator to charge electronic products, capacitors and batteries are indispensable.

Meanwhile, since charging electronic devices with a hand-cranked generator inevitably requires direct current, diodes or even transistors can certainly be found inside the generator. However, if this hand-cranked generator is unavailable, Li Younan can use galena from a button as a detector.

The function of a detector is to perform signal analysis, specifically to separate the audio signal from the high-frequency radio signal received by the coil.

The core approach is to find a unidirectional conductive material, and the best material is naturally a diode.

Next, the capacitor needs to be tuned.

In simple terms, the function of a tuning capacitor is to make the received electromagnetic waves resonate. After resonance, it can amplify one of the frequencies from the messy frequencies, thereby filtering out the other frequencies.

Even without this hand-cranked generator, the tuning capacitor is easy to make.

You can make one simply by drying two pieces of animal leather or using buttons as the two poles of a capacitor and sandwiching an insulating layer in between.

With Li Younan's skill level, he could quickly and roughly adjust the capacitance by changing the overlapping area of ​​the two poles.

If all else fails, you can simply remove the tuning capacitor. Although this will prevent you from tuning stations and only allow you to receive strong stations, it is still the simplest method.

However, with the parts provided by the hand-cranked generator, Li Younan can make a tuning capacitor that works best.

With the core components such as the tuning capacitor, ground wire, coil, and detector in place, Li Younan quickly assembled the crystal radio on the wooden frame.

It must be said that Li Younan, who is proficient in electrical work, carpentry, and radio skills, has assembled a crystal radio that has reached the limit of what is available at the time in terms of aesthetics.

This crystal radio is not only very beautiful, but all its functions are almost up to the standards of modern industrial civilization—of course, such functionality would not be possible if relying entirely on wilderness conditions.

Li Younan looked at his masterpiece with satisfaction and filmed it with a camera: "Now we have a crystal radio, but there is still one most important component that we haven't made, which is the sound-generating component."

There are two approaches to the sound-generating element. One is to directly use high-impedance headphones to hear the weak signal from the crystal radio. The other approach is to solve the problems of signal amplification and power supply. Without the parts provided by this hand-cranked generator, Li Younan would have tried to make a high-impedance listening device using enameled wire, but the sound would be very weak, requiring close contact with the ear to hear, resulting in a poor listening experience.

So Li Younan decided without hesitation to use the second approach: to create a loudspeaker that could produce sound by solving the problems of signal amplification and energy supply.

The hand-cranked generator contains a small lithium battery that can be used as a power source. This lithium battery has a voltage of 5 volts and can be used directly without the need for additional voltage reduction.

The generator also contains coupling capacitors and power filters, which are enough to make a small speaker that can produce sound.

Li Younan's cowhide can come in handy again—cowhide works very well as the diaphragm of this small speaker.

The next step, making the sound-generating device, is the most difficult part of the entire crystal radio. It requires a very solid foundation in electronics, and only someone like Li Younan, who is proficient in circuits and radio skills and has strong hands-on abilities, could have made it by hand in the wilderness.

As the finished product drew closer, Li Younan's excitement grew.

Aside from a few staff members who were increasingly unable to communicate with the players, he was unable to get any outside information.

Finally, before dark, Li Younan finished assembling the crystal radio.

He placed the crystal radio on the bedside table, took a deep breath, and said to the screen, "Now comes the moment of truth."

He placed the tuner on the washer, and immediately a clear yet chaotic radio wave sound came from the speaker.

Li Younan's breathing became a little turbid at this moment, and then he gently moved the adjusting piston.

As the tuner slides on the washer, the sound of the radio waves changes accordingly.

Finally, at a certain point, I could faintly hear the sound of music.

He made further adjustments, and the sound became clearer and clearer, with the noise gradually decreasing. Finally, at a certain point, a melodious song came from the speaker—it was an old song, "Wonderful Tonight," which he didn't know which radio station was playing.

Upon hearing the music, Li Younan felt a lump in her throat and almost burst into tears.

It's been too long since I've heard any sounds from outside.

He gently wiped away the tears from the corners of his eyes, at which point the little ewe looked at him with a puzzled expression.

Overjoyed, Li Younan kicked the ewe's rump, then said regretfully, "What a pity, you're just an animal after all, you can't understand my excitement right now. Wonderful Tonight, damn it, what a wonderful night!"

(End of this chapter)