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Free Web Novel,Novel online - All in hlnovel.com -> Sci-fi -> We live in Nanjing Main Text Chapter 6 Symposium on Amateur Radio Weird Phenomenon and Technology
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- The next day.
When Bai Yang returned home after a day of classes, he saw the mobile radio monitoring vehicle parked downstairs.
A white seven-seater van with a large disc on the roof. For ordinary people, it most often appears in the college entrance examination room. You don¡¯t need to guess Bai Yang to know who drove this car. He couldn¡¯t help being speechless. Uncle is really a big battle.
Back at home, Wang Ning, Zhao Bowen and Lao Die were huddled in their room. Wang Ning was debugging the i725 with headphones on, while Zhao Bowen and Lao Die stood watching.
"What is the standing wave ratio?"
"The standing wave ratio is 1.3."
"That's no problem. I thought it was the impedance mismatch, and the energy was reflected back."
"Nonsense, I use an automatic tuner. You can see that the indicator light of the tuner is green, so there is no problem."
"Then why is the signal detected by the spectrum analyzer so weak? It's not a problem of impedance matching. Where does the energy of the transmitter go?"
"Dad¡ª! Uncle Wang! Uncle Zhao! I'm back!" Bai Yang stood at the door with his schoolbag in his hand, "How long have you been tossing around here?"
Wang Ning took off his earphones, got up and gave Bai Yang the chair.
"About an hour and a half, we started at 8:30 in the evening." Wang Ning took out his mobile phone to check the time, "Just now I called bg4msr and greeted the little girl, she asked when you will come home from school. "
Bai Yang turned sideways and put his schoolbag under the desk. He saw a screwdriver on the desk, "Did you take the radio apart?"
"Open the case and take a look." The old man said, "Your Uncle Wang always suspects that this radio station has been modified by me, so I just asked him to open it and have a look."
"What's the result?" Bai Yang asked.
All three of them spread their hands.
"We can now confirm that it is not the problem of abduction itself."
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The four of them were sitting on the sofa in the living room, and Bai Yang was eating supper with a plate.
The supper is fried noodles, and my mother has already gone to bed after finishing the supper. At this time, my father should also be asleep, but at this moment, a seminar on the strange phenomenon and technology of amateur radio is being held at home.
The guests attending the meeting are:
?Director Wang Ning, representative of Nanjing Radio Management Committee.
?Associate Professor Zhao Bowen, representative of the School of Physics, Nanjing University.
Bai Zhen, the representative of Nanjing's online car-hailing drivers.
? Bai Yang, the third-year student representative of the High School Affiliated to China Southern Airlines in Nanjing.
The meeting was presided over by Bai Zhen, a representative of Nanjing's online car-hailing driver and a retired communication technician.
Wang Ning, a representative of the Nanjing Municipal Radio Management Committee and a member of the presidium of the General Hairstyle Association, director of the National Political and Educational Office, was the first to speak.
"There is a new discovery." Wang Ning said, "We used a spectrum analyzer to measure the radiation field strength at the turn of two and five tonight, and found a very strange phenomenon."
"What's the phenomenon?" Bai Yang swallowed the noodles, licked the oil on his lips, and raised his head to ask.
"Two-five turn signal is weak, Xiao Yang, do you remember? When we used a spectrum analyzer to monitor the signal two days ago, we couldn't hear the signal of bg4msr, and on the other hand, the signal at turn-two-five was also very weak." Wang Ning said, "At first I thought it was a serious mismatch between the impedance of the radio station and the antenna, but I tested it with a standing wave meter and found that there was no problem."
"I know." Bai Yang nodded, "The sky tune is always green, of course it's no problem."
"So we tried a few more frequency bands." Wang Ning continued, "It's very strange, whether it is six-meter wave, two-meter wave, or 70-centimeter wave, all other frequency bands are normal. Spectrum analyzer or standing wave meter to measure, 20 watts is 20 watts, only 14 MHz, once entering 14 MHz, the signal strength of the two-five transmitter will be greatly attenuated, and it is conservatively estimated that the transmitted power is less than that of the radio station One-tenth of the power."
"Where did the remaining nine-tenths of the energy go?"
Bai Yang was taken aback, and put down the plate in his hand.
"This is also a question we are thinking about." Zhao Bowen said, "Where does the remaining energy go?"
"Energy cannot disappear out of thin air, energy conservation is the basic law, right?" Bai Yang asked, "If energy is not sent out through the antenna, then it is reflected back."
It is common sense that radio stations emit electromagnetic waves through antennas.
The electromagnetic waves generated by the transmitter are conducted to the antenna through the feeder (coaxial cable), and then radiated to the outside world through the antenna. This is the basic propagation process of radio signals-but the electromagnetic waves generated by the transmitter cannot be radiated out completely.For a radio station with such a high rate, the energy must be lost during the propagation process. Some of the radio waves will be reflected back by the original path during the transmission to the antenna, and cannot be radiated smoothly. To put it bluntly, they are blocked back.
The more radio waves are blocked, the lower the efficiency of the radio station, and the less they are blocked, the higher the efficiency of the radio station.
If there are too many reflections and the radio waves are blocked too much, the energy will be accumulated in the radio and converted into heat energy, which will burn out the transmitter.
This is a problem that all hams will pay attention to.
In order to avoid burning the machine, the majority of hams have mastered the key factors that determine whether electromagnetic waves can be emitted efficiently. One is called resistance, the other is called reactance, and together they are called impedance.
If the impedance of the feeder line is consistent with the impedance of the antenna, the electromagnetic waves generated by the transmitter can be emitted smoothly, and the bladder will not explode if the urethra is unobstructed. This is called impedance matching.
So how to judge whether the impedance matches?
The most commonly used method is the standing wave meter. Use the standing wave meter to measure the standing wave ratio. The closer the standing wave ratio is to 1, the more matching the impedance will be. Otherwise, the machine will burn out.
Some old toads look like the end of the world when the standing wave ratio is greater than 1.1.
"Usually this is the case. Everyone knows that energy conservation is the basic law, but it doesn't work on your machine. The radio wave is not reflected back, but disappears inexplicably If you don't believe me, Xiao Yang, you can go to Try it." Wang Ning pointed to the door.
Bai Yang got into the room and turned on the radio, Wang Ning followed in with the spectrum analyzer in his arms, and the two began to experiment.
"Increase the power a little." Wang Ning reminded, "Twenty watts."
"fine?"
"It's okay." Wang Ning said.
"Will you not bother me?"
"I'm just innocent."
Bai Yang increased the transmission power of the 725 to twenty watts, and first pressed the transmission button on the frequency of 14.255 MHz.
A small peak rises on the oscilloscope of the spectrum analyzer.
"Okay, then adjust the frequency casually." Wang Ning said.
Bai Yang casually turned the radio's FM knob, and the numbers on the LCD jumped wildly, finally staying at 50 MHz.
Press the launch button again, and the peak on the spectrum analyzer suddenly rises, just like a balloon is suddenly blown up.
"The spectrum meter measures the radiation field strength. Radiation intensity is related to power and has nothing to do with frequency. It stands to reason that if you maintain a transmission power of 20 watts, whether it is 14 MHz or 50 MHz, the signal strength emitted by the radio station should be consistent. "Wang Ning said, "However, it is very strange that this 25G is very strange. Once it enters 14 MHz, the signal strength monitored by the spectrum analyzer will drop sharply. The received signal strength was less than two watts."
"What does this mean?"
"This shows that not only bg4msr's signal is weird, but this radio station is also weird." Zhao Bowen stood behind them, "Once it enters the frequency of 14 MHz, the energy radiated by two to five disappears. We use three Connecting the spectrum analyzer to the antenna through the line can't be monitored. It doesn't help by any means. It doesn't help to increase the power to 50 watts or 100 watts. This means that it is not even transmitted to the antenna through the feeder line. We can only think that The energy is lost inside the station."
"Where did the signal go?" Bai Yang asked, "Through time and space?"
"We can't make such a conclusion yet." Zhao Bowen shook his head, "Our current experimental conditions are very limited, and the tests we have done are quite rough. It is best to find an anechoic chamber for testing."
"Where is the electromagnetic anechoic chamber?" Bai Zhen asked.
Zhao Bowen thought for a moment, "Nanjing University of Technology should have one, I'll ask if I can borrow it."
Although it is said so, no conclusion can be made without further experiments, but Zhao Bowen, Bai Zhen and Wang Ning also know in their hearts that if the experimental conditions are changed, the result may still be the same.
None of the three adults present believed in the explanation of the hyperspace communication, but none of them could explain the inexplicably disappearing signal.
"I admit that this matter is beyond my understanding." Wang Ning said, "It's not a radio problem."
"Let's put the anechoic chamber aside, old Zhao, when you can borrow it." Bai Zhen said, "The crux of the problem is not here. The most important thing is to find out whether bg4msr really lives in twenty years. This is key problem."
"Really." Bai Yang said, "I have verified it."
"We know that you have verified it." Zhao Bowen said, "But the isolated evidence cannot be cited. The experiment is only meaningful if it can be repeated."
Bai Yang was taken aback for a moment, "Soyou are also planning to create a time capsule?"
Sure enough, it has developed to this point, Bai Yang thought, no one can believe an absurd fact with just a few words, so if they want to be convinced, they have to verify it with their own hands, seeing is believing.
However, regarding the many problems of the slow delivery of time, Bai Yang has stepped on the pit for them. They only need to cross the river by feeling the stones and follow the successful path that Bai Yang wades out to copy the previous methods. With a smear of black poplar, Uncle Zhao, Uncle Wang and Dad are much simpler.
"If you also want to send time capsules." Bai Yang said, "Be sure to pay attention to a few key issues, otherwise there is a high probability of failure. This is a precious experience I bought back with blood and tears. You must remember it well Number one!""Sure enough, it has developed to this point, Bai Yang thought to himself, no one can believe an absurd fact with just a few words, so if they want to be convinced, they have to verify it with their own hands, seeing is believing.
However, regarding the many problems of the slow delivery of time, Bai Yang has stepped on the pit for them. They only need to cross the river by feeling the stones and follow the successful path that Bai Yang wades out to copy the previous methods. With a smear of black poplar, Uncle Zhao, Uncle Wang and Dad are much simpler.
"If you also want to send time capsules." Bai Yang said, "You must pay attention to a few key issues, otherwise there is a high probability of failure. This is a precious experience I bought back with blood and tears, so I must remember it well Number one!? - Didn't finish reading? Add this book to your favoritesI'm a member and bookmarked this chapterCopy the address of this book and recommend it to your friends for pointsChapter error? Click here to report
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