Banxia held a small green PCB board in her hand and looked at the light. It was slightly larger than her thumb. There was a wire more than ten centimeters long hanging from it. It was a thin white wire, soldered at both ends.

There are square circuit boards of the same size. The board at one end of Banxia's hand is marked with a vague "TX", and the board at the other end is marked with "RX". This thing is plugged into the repeater.

Plug one end into the transmitter and the other end into the receiver to connect the two base stations.

The PCB is covered with green solder mask, and regular wiring can be seen under the thin solder mask. This circuit board is small and simple, with neatly arranged silver strips of pads marked with white

English abbreviations.

"Hmm... I'm obsessed with CAUDIO..."

Banxia looked at it carefully.

"PTT."

"GND."

"RXAUDIO."

“CO Meat T.”

She didn't know what the abbreviations meant, but she could guess what the pins meant.

This is the simplest circuit board. It is so simple that it does not even have the most basic components. It weighs only a few grams in your hand. However, it embodies the highest wisdom of mankind’s third industrial revolution. The idea of ​​integration starts from this piece.

Born from a small piece of plastic, PCB boards have since replaced complex and bulky physical cables and lines. People use printing to two-dimensionalize sophisticated circuits like drawings, lay them on a flat surface, and create complex designs like cities.

Minimized to a millimeter, a huge information kingdom is built.

How far did human civilization develop before the world was destroyed?

The girl raised her bare feet, rocked the chair creakingly, raised the circuit board in her hand, squinted one eye, and focused on the small round hole on the circuit board. She might understand the teacher's sadness.

And pain, this magical creation was placed in front of her, but she couldn't understand it.

This is an ability that humans have ever had.

Now it's lost.

Banxia recalled the days when the teacher was still there, when she was still young. The teacher took her everywhere to pick up rubbish, and used the picked rubbish to build a strong fortress bit by bit.

The teacher is from the old era, and she knows the world before the apocalypse very well. Banxia has guessed the teacher's occupation, but the latter's powerful ability as a generalist makes it impossible for Banxia to confirm what she was doing before the disaster struck.

Yes, the teacher is good at survival in the wild and has extremely accurate marksmanship. Banxia thought she was a soldier, but she also knew how to build an electrical network and repair complex household appliances. She was like an electrician. What surprised Banxia most was that the teacher had studied

For a long, long time, the teacher had collected a lot of information about astronomy and aerospace engineering (Ban Xia didn’t know what astronomy and aerospace engineering were, Bai Yang told her about these two words), but in the end she lost all of them.

Burned.

In those years, the teacher sat in the room reading books and drawing pictures, and asked Banxia to go aside and play in the mud. Occasionally, Banxia sneaked into the room, and you could see the walls covered with scraps of paper.

"Teacher is definitely saving the world!" Banxia said to Bai Yang, "She is looking for ways to get rid of this world-destroying disaster!"

"But there are only two of you left in the world." Bai Yang asked, "How can we save this? Can we bring everyone back to life?"

"I don't know about that, she must be looking for a way." Banxia said, "She is the only person who survived the disaster for such a powerful teacher! One in a billion, such a person

Isn’t he the savior destined by God?”

"And you, Miss, you are also a survivor."

"I'm just a person who was saved by her. I'm the kind of person who lags behind." Banxia said, "Without her, I wouldn't be able to survive now. Without me, she should be able to survive until now."

"It's a pity that the teacher didn't leave any useful information." Bai Yang sighed.

"She burned all her information." Banxia said, "Who could have known that this would happen? I can contact you."

"It would be great if she was left to you." Bai Yang scratched his head, "Then we wouldn't be as confused as we are now. We don't know what happened or the reason."

"But she didn't leave it for me. If you had contacted us five or six years earlier, you would have been able to talk to the teacher." Banxia said, "We are traveling through time and space anyway, why can't you push the time forward five years?"

Year? Five years ago, the teacher was still alive, and she knew everything."

"This is not something I can decide, Miss." The other end of the radio station said leisurely, "God has given us this rare opportunity. There is no way to pick and choose. I also want to get through to your teacher."

"Oh?" The girl raised her eyebrows, "Don't you want to get through to me?"

"No...I didn't mean that." Bai Yang stuttered immediately, "I meant that your teacher is more useful..."

"I am useless?"

"You are useful!" Bai Yang said firmly.

"What good am I?"

"You...you are the last hope of all mankind from ancient times to the present, the most important last person in human history, the eldest lady with a body of thousands of gold and a priceless treasure, the highest IQ in the world, the most accurate marksmanship, the best archery skills, and the most beautiful appearance.

, the person with the best figure!" Bai Yang finished in one breath.

Banxia's eyes rolled around, her lips pursed upwards in a small arc, and she made a soft nasal sound.

"snort."

·

·

·

Thursday.

Half of Wang Ning's fat body was leaning out of the window, holding a two-meter-long whip antenna high in his hand, sweating profusely.

He put on his headphones and listened carefully for a while, then shouted toward the community: "I can't hear anything! Lao Bai, have you sent your message?"

"No!"

Bai Zhen stood far away on the edge of the lawn of the community downstairs, with a folding wooden table in front of him and a black digital amateur radio station on it. He tilted his head and held the phone between his neck, holding Baofeng in one hand.

UV5R amateur radio handset, digital radio on the debugging table in the other hand.

"Then hurry up! I can't maintain this position for long!" Wang Ning roared, "My waist is going to break!"

"Okay...yes, okay, no problem, I'll give it to you later."

"Old Bai, have you delivered your fucking message?"

"No!"

"Then what are you talking about? What are you talking about?"

"Old Zhao is calling me!"

"How can he come up with so many nonsense!"

"How do I know where he talks so much!" Bai Zhen yelled upstairs, then lowered his head to make a phone call, "Huh? He's not talking about you, he's saying that his father talks too much.

"

This is their sixth experiment today.

The experiment was quite large. Repeaters, base stations, and spectrum analyzers were all used. Wang Ning and Bai Zhen had already completed the initial setup of the remote control system. They started the experiment at nine o'clock this morning and were busy until four o'clock in the afternoon.

Constantly debug the equipment in order to achieve the best condition.

The distance between different devices is widened, and they are placed as far away from each other as possible.

The repeater station is connected to the second-hand I725 and is placed on the desk in Baiyang's room. This is because the second-hand I725 shortwave station needs to borrow the DP antenna of Baiyang Radio. The 14MHZ dipole antenna is twenty meters long, like a super large

The clothesline is also placed on the roof. It cannot be temporarily installed and can only be borrowed.

The antenna that the repeater station needs to use is a 144MHZ whip antenna, two meters long. They gave up the duplexer in the modification plan, so they simply used two antennas, one for the transmitter and one for the receiver.

, everyone has their own use, Wang Ning took it in his hand and held it out of the window.

In order to avoid mutual interference, Wang Ning should keep the two antennas as far away as possible, so at this moment he looks like Ultraman leaning out the window with his hands raised.

To be honest, this posture is a bit scary, as if it is about to be launched into the sky and fly into the universe at any time.

At the same time, Bai Zhen moved another amateur radio station, I705, which he borrowed from someone.

Bai Zhen took a folding table downstairs and set it up on the lawn of the community, but was kicked out by the security guard.

He changed a place, set up a table on the alley, set up the I705 amateur digital radio, set up the antenna, and attracted security guards. He spent a long time arguing with the community security guards.

The new security guard believed that the middle-aged man acted suspiciously, had suspicious equipment, and had suspicious credentials.

Bai Zhen asked, don’t you know what HAM is? I am HAM.

The security guard said that if you are a toad, please go back to the pool.

Bai Zhen holds the UV5R handheld device in his hand, with the I705 on the table and an antenna beside him. He is responsible for testing the remote control system in the command post.

The following signal links will be formed between these devices:

When testing reception, Bai Zhen used UV5R to send calls outside. The signal was received by the G repeater station, and the repeater station's receiver transmitted the signal to I725.

When testing the transmission, Wang Ning used the I725 in the room to send the signal. The I725 transmitted the signal to the G repeater station. The transmitter of the repeater station sent the signal to Bai Zhen, and Bai Zhen's I705 amateur radio station was responsible for receiving it.

If there is no problem with sending and receiving, then BG4MSR can replicate an identical system.

Due to a serious shortage of manpower, Wang Ning and Bai Zhen could only act as two people. Bai Zhen went downstairs with a handheld platform and kept distance, while Wang Ning wore headphones to listen to the signal, and at the same time held up the antenna to act as a human being.
Chapter completed!