Chapter 74 What does a teacher do?
Banxia held a small green PCB board in her hand and looked at it against the light. It was slightly larger than her thumb, with a wire about ten centimeters long hanging from the bottom. It was a thin white wire with square circuit boards of the same size soldered on both ends. The board on the end in Banxia's hand was marked with an unclear "TX" and the board on the other end was marked with "RX". This thing was plugged into the repeater station. One end of it was plugged into the transmitter and the other end was plugged into the receiver, connecting the two base stations.
The PCB board 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 long strips of pads marked with white English abbreviations.
"Hmm... MIC AUDIO..."
Banxia looked at it carefully.
"PTT."
"GND."
"RX AUDIO."
"COR OUT."
She didn't understand what the abbreviations meant, but she could guess that they marked the functions of the pins.
This is a most rudimentary circuit board, so rudimentary that it does not even have the most basic components. It weighs only a few grams in the hand, but it embodies the highest wisdom of the third industrial revolution of mankind. The idea of integration was born from this tiny piece of plastic. From then on, PCB boards replaced complex and bulky physical cables and lines. People used printing to two-dimensionalize precise and complex circuits like drawing, and laid them on a flat surface, miniaturizing complex designs like cities to millimeters, and building a huge information kingdom.
To what extent had human civilization developed before the world was destroyed?
The girl lifted up her bare feet, rocked the chair with a creaking sound, raised the circuit board in her hand, squinted one eye, and focused her sight on the small round through hole on the circuit board. She might be able to understand the teacher's sadness and pain, but she could not understand this magical creation in front of her.
This is a capability that humans once had.
But now it's lost.
Banxia recalled the days when her teacher was still alive. She was still young at that time, and the teacher took her to pick up garbage everywhere, and built a solid fortress bit by bit with the garbage picked up.
The teacher was from the old times and she knew a lot about the world before the end of the world. Banxia had guessed about the teacher's occupation, but the latter's powerful abilities, like a jack of all trades, made it impossible for Banxia to confirm what she was doing before the disaster. The teacher was good at wild survival and had very accurate marksmanship. Banxia thought she was a soldier, but she also knew how to build an electricity network and repair complex household appliances, just like an electrician. What surprised Banxia most was that the teacher had studied astronomy and aerospace engineering for a very long time (Banxia didn't know what astronomy and aerospace engineering were, these two words were told to her by Bai Yang). The teacher once collected a lot of information, but in the end she burned it all.
During those years, the teacher sat in the room flipping through books and drawing pictures, and asked Banxia to go aside and play in the mud. Occasionally, Banxia sneaked into the room and saw the walls were covered with draft papers.
"The teacher is definitely saving the world!" Banxia said to Baiyang, "She is looking for a way 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 them? Can we bring everyone back to life?"
"I don't know about that. She must be looking for a way." Banxia said, "Teacher is such a great person, but she is the only one who survived the disaster! One in billions, isn't such a person the savior destined by God?"
"And you, Miss, you are also a survivor."
"I'm just the one she saved, and I'm the one who holds her back." Banxia said, "Without her, I wouldn't be alive today. Without me, she should be alive today."
"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 left it to you." Bai Yang scratched his head, "Then we wouldn't be so confused like we are now, not knowing what happened or why."
"But she didn't leave it to me. If you had contacted us five or six years earlier, you would have been able to talk to the teacher." Banxia said, "Anyway, we are traveling through time and space, so why can't you push the time forward five years? The teacher was still alive five years ago, and she knew everything."
"This is not something I can decide, Miss." The person on the other end of the radio said leisurely, "It is already a rare opportunity that God has given us. How can we be picky? I also want to know that it is your teacher."
"Oh?" The girl raised her eyebrows. "You don't want to get in touch with me?"
"No... I... I didn't mean that." Bai Yang stuttered, "I meant that your teacher is more useful..."
"I'm useless?"
"You are useful!" Bai Yang said firmly.
"What use am I?"
"You...you are the last hope of all mankind from ancient times to the present, the last most important person in human history, the eldest lady who is worth a lot of money and a priceless treasure, the person with the highest IQ, the most accurate shooting, the best archery, the most beautiful appearance, and the best figure in the world!" Bai Yang said it in one breath.
Banxia's eyes rolled around, her lips pursed up in a small arc, and she made a soft nasal sound.
"snort."
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Thursday.
Half of Wang Ning's fat body was leaning out of the window, with two mop sticks held high in his hands, on which were tied two-meter-long whip antennas, and he was sweating profusely.
He put on his headphones and listened carefully for a while, then shouted to the community: "I can't hear anything! Lao Bai, did you send a message--?"
"No--!"
Bai Zhen was standing far away on the edge of the lawn in the community downstairs, with a folding wooden table in front of him and a black digital amateur radio on the table. He tilted his head and clamped the mobile phone with his neck, holding the Baofeng UV5R amateur radio walkie-talkie in one hand and debugging the digital radio on the table with the other hand.
“Then hurry up! I can’t hold this position for too long!” Wang Ning screamed, “My waist is going to break!”
"Okay...yeah, ok, no problem, I'll give it to you later."
"Old White, did you send the fucking message—?"
"No--!"
"What are you blabbering about, then? What are you talking about—?"
"Old Zhao is calling me——!"
"Why does he have so much to say——!"
"How do I know where he gets all that bullshit from--!" Bai Zhen first yelled at the people upstairs, then lowered his head to make a phone call, "Huh? He's not talking about you, he's talking about his dad's bullshit."
This was their sixth experiment of the day.
The experiment was quite large, with repeater stations, base stations and spectrum analyzers all being used. Wang Ning and Bai Zhen had already preliminarily built 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 debugging the equipment in order to achieve the best condition.
The distance between different devices is pulled far apart, and they are placed as far away from each other as possible.
The relay station and the second-hand Icom725 were connected together and placed on the desk in Baiyang's room - this was because the second-hand Icom725 shortwave station needed to borrow the DP antenna from Baiyang Radio Station. The 14MHZ dipole antenna was a full twenty meters long and was hung on the roof like an oversized clothesline. It was impossible to temporarily use it, so they had to borrow an existing one.
The antenna needed for the relay station is a 144MHZ whip antenna, two meters in length. They gave up the duplexer in the modification plan, so they simply used two antennas, one for the transmitter and one for the receiver, each using its own antenna, both held in Wang Ning's hands and held outside the window.
In order to avoid mutual interference, Wang Ning should keep the two antennas as far apart as possible, so at this moment he looks like an Ultraman with his hands raised and leaning out of the window.
To be honest, this posture is a bit scary, as if it is about to launch into the universe at any time.
At the same time, Bai Zhen moved in an amateur radio station, which was an Icom705 that he borrowed from someone.
Bai Zhen went downstairs with a folding table and set it up on the lawn of the community, but was driven out by the security guard.
He moved to another place, set up a table on the path, placed an Icom705 amateur digital radio on it, set up the antenna, and attracted the security guard. He spent a long time arguing with the community security guard.
The new security guard thought that the middle-aged man's behavior, equipment and ID were suspicious.
Bai Zhen asked, "Don't you know what HAM is? I am HAM."
The security guard said if you are a toad, please go back into the pool.
Bai Zhen holds a UV5R walkie-talkie in his hand, an Icom705 is placed on the table, and an antenna is set up beside him. He is responsible for testing the remote control system in the command center.
The following signal links will be formed between these devices:
When testing the reception, Bai Zhen used UV5R to send a call outside, and the signal was received by the GR3188 repeater station. The receiver of the repeater station transmitted the signal to Icom725.
During the test transmission, Wang Ning used the Icom725 in the room to send the signal. The Icom725 transmitted the signal to the GR3188 repeater station, and the repeater station's transmitter sent the signal to Bai Zhen, who was then responsible for receiving it using Bai Zhen's Icom705 amateur radio station.
If there are no problems with sending and receiving, then BG4MSR can replicate an identical system.
Due to severe shortage of manpower, Wang Ning and Bai Zhen could only do the work of two people. Bai Zhen went downstairs with the walkie-talkie and kept a distance, while Wang Ning wore headphones to listen to the signal and held up the antenna to act as a human frame.
"Attention, attention, all departments." Bai Zhen pressed the PTT button of UV5R, "Reverse the Future and Save the World Amateur Radio Emergency Command Center, the sixth experiment of the remote control system begins now!"
(End of this chapter)
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