We Live In Nanjing

  Chapter 46 Seminar on Amateur Radio Bizarre Phenomenon and Technology

  The next day.

  When Bai Yang returned home from a day’s course, he saw the mobile radio monitoring vehicle parked downstairs.

A white seven-seater van with a large disk on the roof. For ordinary people, the most common place for it to appear is the college entrance examination room. You don’t need to guess Bai Yang to know who drove the car. I can’t help but be speechless, Wang Uncle is really in a big battle.

   Back home, Wang Ning, Zhao Bowen and Dad were squeezing in their room. Wang Ning was debugging Icom725 with headphones on, while Zhao Bowen and Dad stood on both sides and watched.

  "What is the standing wave ratio?"

  "Standing wave ratio 1.3."

   "That's okay, I thought it was impedance mismatch, and the energy was reflected back."

   "Nonsense, the automatic sky adjustment I used, you see that the sky adjustment indicator is green, that's okay."

  "Then why is the signal monitored by the spectrum analyzer so weak? It is not a problem of impedance matching. Where does the energy of the transmitter go?"

  "Dad——! Uncle Wang! Uncle Zhao! I'm back!" Bai Yang stood at the door carrying a schoolbag, "How long have you been tossing here?"

  Wang Ning took off the headphones, got up and gave the chair to Bai Yang.

"It's about an hour and a half. We started at 8:30 in the evening." Wang Ning took out his mobile phone and glanced at the time. "I just called BG4MSR and greeted the little girl. She asked you when you will come home from school. "

  Bai Yang came over and put his schoolbag under the desk. He saw a screwdriver on the desk, "Did you take the radio apart?"

  "Open the shell 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 let him open it."

   "What's the result?" Bai Yang asked.

  The three of them all spread their hands.

  "We can now confirm that it is not the problem of abduction itself."

  ·

  ·

  ·

  Four people were sitting on the sofa in the living room, and Bai Yang was eating supper with plates.

  Supper is fried noodles. My mother is already asleep after the supper. At this time, my father should have fallen asleep too, but at the moment, a seminar on amateur radio strange phenomena and technology 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 driver.

  Bai Yang, the representative of senior high school students from China Southern Airlines Affiliated Middle School in Nanjing.

  Presided over the meeting was Bai Zhen, a representative of Nanjing's online car-hailing driver and a retired communications technology soldier.

  Wang Ning, representative of the Nanjing Radio Management Committee and director of the National Politics and Education Office, was the first to speak.

   "There is a new discovery." Wang Ning said, "We used a spectrum analyzer to measure the radiated field strength of the two-fifth quarter tonight and found a very strange phenomenon."

   "What's the phenomenon?" Bai Yang swallowed the noodles, licked the oil on his lips, raised his head and asked.

"The signal of turning two to five is weak, do you remember Xiao Yang? When we used a spectrum analyzer to monitor the signal two days ago, on the one hand, the signal of BG4MSR was not heard, on the other hand, the signal of turning two to five was also very weak." Wang Ning said, “At first I thought it was a serious mismatch between the impedance of the radio and the antenna, but it was found to be no problem when measured with a standing wave meter.”

   "I know." Bai Yang nodded, "The sky is always green, of course it's okay."

"So we tried a few more frequency bands." Wang Ning continued, "It is very strange, whether it is a six-meter wave, a two-meter wave, or a 70-centimeter wave. All other frequency bands are normal. The spectrum analyzer is still a standing wave meter. Twenty watts is 20 watts, only 14 MHz. Once it enters 14 MHz, the signal strength of the two-five transmitter will be greatly attenuated. It is conservatively estimated that the transmitted power is less than the radio station. One-tenth of the power."

   "Where did the remaining nine-tenths of energy go?"

  Poplar was taken aback, put down the plate in his hand.

  "This is also the question we are thinking about." Zhao Bowen said, "Where did the remaining energy go?"

   "Energy can't disappear out of thin air, energy conservation is the basic law, right?" Bai Yang asked, "If energy is not emitted 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 100%, and there is no efficiency in the world. For such a high radio station, energy must be lost during the propagation process, and some of the radio waves will be reflected back by the original path during the process of being transmitted to the antenna, and cannot be radiated smoothly. To put it bluntly, it is blocked.

  The more radio waves are blocked, the lower the efficiency of the radio station, and the less the radio waves are blocked, the higher the efficiency of the radio station will naturally be.

  If there is too much reflection and the radio waves are blocked too much, the energy will be accumulated in the radio and converted into heat, 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 the combination is called impedance.

  The impedance of the feeder 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 clear. This is called impedance matching.

  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 the impedance matches. Otherwise, the machine will be burned.

  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 the conservation of energy is the basic law, but it won’t work on your turn two or five. The radio waves are not reflected back, but disappear inexplicably... If you don’t believe me, Xiao Yang, you can go. Try it." Wang Ning pointed to the door of the room.

  Poplar got into the room and turned on the radio station. Wang Ning followed in with the spectrum analyzer, and the two began the experiment.

   "Increase the power a bit." Wang Ning reminded, "Twenty watts."

"fine?"

   "It's okay." Wang Ning said.

   "I can't help but trouble me?"

   "I'm just no committee."

  Poplar increased the 725's transmit power to 20 watts, first press the transmit button on the frequency of 14.255 MHz.

  A small peak is raised on the oscilloscope of the spectrum analyzer.

   "Okay, then just adjust the frequency." Wang Ning said.

  Poplar casually twisted the radio's FM knob, and the numbers on the LCD display jumped wildly, and finally stayed at 50 MHz.

  Press the launch button again, the wave crest on the spectrum analyzer suddenly rises, just like a balloon is suddenly blown up, and the reading skyrocketed.

"The spectrum analyzer measures the radiated field strength. The radiant strength is related to power and has nothing to do with frequency. Logically speaking, 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 the same. "Wang Ning said, "However, it is very strange for this two-to-five device. Once it enters 14 MHz, the signal strength monitored by the spectrum analyzer drops drastically. The received signal strength is less than two watts."

   "What does this mean?"

"This shows that not only the BG4MSR signal is weird, but this station is also weird." Zhao Bowen stood behind them, "Once it enters the 14 MHz frequency, the energy radiated by turning two or five will disappear. We use three. Connecting the spectrum analyzer to the antenna through the wire can not monitor it. It will not help by any means. It is useless to increase the power to 50 watts and 100 watts. This shows that it is not even transmitted to the antenna through the feeder. We can only think The energy disappears inside the radio."

  "Where did the signal go?" Bai Yang asked, "has traveled through time and space?"

  "We can't make this kind of judgment for the time being." Zhao Bowen shook his head, "Our current experimental conditions are very limited, and the tests we do are quite rough. It's best to find an anechoic chamber to test it."

   "Where is the electromagnetic anechoic chamber?" Bai Zhen asked.

  Zhao Bowen thought for a moment, “Southern Institute of Technology should have one. I’m asking if I can borrow it.”

  Although it is said that it is not possible to make a judgment without further experimentation, Zhao Bowen, Bai Zhen and Wang Ning knew in his heart that the experiment conditions were changed, and the result might still be the same.

  The three adults present did not believe in the explanation of the time-space communication, but none of them could explain the signal that disappeared inexplicably.

   "I admit that this matter is beyond my understanding." Wang Ning said, "It is not a radio problem."

"Let's put aside the radio anechoic chamber first, Lao Zhao, when can you borrow it?" Bai Zhen said. "The key to the problem is not here. The most important thing is to figure out whether the BG4MSR really lives in twenty years. This is the core issue."

   "Really." Bai Yang said, "I have verified it."

   "We know that you have verified it." Zhao Bowen said, "but no evidence is provided. The experiment is only meaningful if it can be repeated."

   Bai Yang was taken aback, "So...you are planning to do a time capsule too?"

  Sure enough, Bai Yang thought to himself that no one can believe a ridiculous fact with just a few words, so if they are 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 already stepped on the pits for them. They only need to cross the river by feeling the stones and follow the successful path of Bai Yang to copy the way of the predecessors. Compared with the first attempt, the eyes A smear of black poplar, Uncle Zhao, Uncle Wang and Dad are too simple.

"If you also want to give time capsules." Bai Yang said, "you must pay attention to a few key issues, otherwise there is a high probability of failure. This is the precious experience I exchanged with blood and tears. I must remember... the first point! "

  (End of this chapter)