Chapter 46 Amateur Radio Strange Phenomena and Technology Seminar

The next day.

When Bai Yang finished his classes for the day and went home, he saw the mobile radio monitoring vehicle parked downstairs.

It was a white seven-seater van with a large round plate on its roof. For ordinary people, the most common place it appeared was the college entrance examination venue. Bai Yang knew who drove the car without having to guess. He could not help but be amazed. Uncle Wang really made a big fuss.

When they got home, Wang Ning, Zhao Bowen and his father were crowded in their own room. Wang Ning was debugging Icom725 with headphones on, while Zhao Bowen and his father were standing on both sides watching.

“What’s the standing wave ratio?”

“Standing wave ratio 1.3.”

"That's no problem. I thought it was an impedance mismatch and the energy was reflected back."

"Nonsense, I use the automatic antenna tuning. You see the antenna tuning indicator light is green, so there is no problem."

"Then why is the signal detected by the spectrum analyzer so weak? It's not an impedance matching problem. Where did the energy of the transmitter go?"

"Dad! Uncle Wang! Uncle Zhao! I'm back!" Bai Yang stood at the door with his schoolbag in hand. "How long have you been here?"

Wang Ning took off his headphones, stood up and gave his chair to Bai Yang.

"About an hour and a half. We started at 8:30 in the evening." Wang Ning took out his phone and checked the time. "I just called BG4MSR and greeted the girl. She asked when you will be home from school."

Bai Yang turned sideways and put his schoolbag under the desk. He saw a screwdriver on the desk and asked, "Did you disassemble the radio?"

"I opened the case and took a look." Dad said, "Your uncle Wang always suspected that I had modified this radio, so I just asked him to open it and take 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 kidnapping itself that is the problem."

·

·

·

Four people sat on the sofa in the living room, and Bai Yang was eating a midnight snack with a plate in his hand.

The midnight snack was fried noodles. Mom went to bed after making it. Dad should have been asleep at this time, but a seminar on amateur radio strange phenomena and technologies was being held at home.

Guests attending the meeting included:

Director Wang Ning represented the Nanjing Radio Management Committee.

Representative of the School of Physics of Nanjing University is Associate Professor Zhao Bowen.

Bai Zhen, a representative of online ride-hailing drivers in Nanjing.

Bai Yang, a representative of the senior high school students from Nanjing University of Aeronautics and Astronautics Affiliated High School.

The meeting was chaired by Bai Zhen, a representative of Nanjing's online ride-hailing drivers and a retired communications technician.

Wang Ning, representative of the Nanjing Radio Management Committee and member of the presidium of the National Association of Directors of Political and Educational Departments, was the first to speak.

"We have made a new discovery," Wang Ning said. "Tonight we used a spectrum analyzer to measure the radiation intensity of Guailianwu and found a very strange phenomenon."

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

"The signal at 25° is weak, Xiao Yang, do you remember? When we used a spectrum analyzer to monitor the signal a few days ago, we couldn't hear the signal from BG4MSR, and the signal at 25° was also very weak." Wang Ning said, "At first I thought it was a serious impedance mismatch between the radio and the antenna, but after testing it with a standing wave meter, I found that there was no problem."

"I know." Bai Yang nodded. "The weather station has been green all the time, so of course there is no problem."

"So we tried a few more frequency bands." Wang Ning continued, "It was very strange. Whether it was the six-meter wave, the two-meter wave, or the 70-centimeter wave, all other frequency bands were normal. Whether it was measured with a spectrum analyzer or a standing wave meter, 20 watts was 20 watts. Only 14 MHz, once it entered 14 MHz, the signal strength of the 25-meter transmitter would be greatly attenuated. Conservative estimates show that the transmitted power is less than one-tenth of the radio station's power."

“Where did the remaining nine-tenths of the energy go?”

Bai Yang was stunned 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 can't disappear out of thin air. The law of conservation of energy is a basic law, right?" Bai Yang asked. "If the 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 transmitted 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. However, it is impossible for the electromagnetic waves generated by the transmitter to be radiated 100%. There is no such efficient radio station in the world. Energy must be lost in the process of propagation. Some of the radio waves will be reflected back by the original path in the process of transmission to the antenna and cannot be radiated smoothly. To put it bluntly, they are blocked.

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

If too much is reflected back and the radio waves are blocked too much, the energy will accumulate inside the radio station and be converted into heat energy, burning out the transmitter.

This is an issue 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, the urethra is unobstructed and the bladder will not explode. This is called impedance matching.

So how do you determine whether the impedance is matched?

The most commonly used method is the standing wave meter, which is used to measure the standing wave ratio. The closer the standing wave ratio is to 1, the more matched the impedance is. Otherwise, the machine will burn out.

Some old fools think it's the end of the world when they see the standing wave ratio is greater than 1.1.

"Normally this is the case. Everyone knows that conservation of energy is a basic law. But it doesn't work on your machine. The radio waves are not reflected back, but disappear inexplicably... If you don't believe it, Xiao Yang, you can go and try it." Wang Ning pointed to the door.

Bai Yang went into the room and turned on the radio. Wang Ning followed in with a spectrum analyzer, and the two began the experiment.

"Increase the power a bit." Wang Ning reminded, "20 watts."

"fine?"

"It's okay." Wang Ning said.

"Will Wuwei not trouble me?"

“I am the No Committee.”

Bai Yang increased the transmission power of 725 to 20 watts and pressed the transmit button at a frequency of 14.255 MHz.

A small peak appears on the oscilloscope of the spectrum analyzer.

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

Bai Yang casually turned the FM knob of the radio, and the numbers on the LCD display jumped around and finally stopped at 50 MHz.

When the transmit button is pressed again, the peak on the spectrum analyzer suddenly rises, like a balloon being suddenly blown up, and the reading soars.

"The spectrum analyzer measures the radiation field strength, which is related to power and has nothing to do with frequency. Logically, if you maintain a transmission power of 20 watts, the signal strength emitted by the radio station should be the same, whether it is 14 MHz or 50 MHz." Wang Ning said, "But this Gualiangwu is very strange. Once it enters 14 MHz, the signal strength detected by the spectrum analyzer drops sharply. Obviously, Gualiangwu is still running at 20 watts, but the signal strength received by the spectrum analyzer is less than 2 watts."

"What does this mean?"

"This shows that not only is there something wrong with the signal of BG4MSR, but also with this radio station." Zhao Bowen stood behind them. "Once it enters the frequency of 14 MHz, the energy radiated by the two-way radio disappears. We can't detect it by connecting the spectrum analyzer to the antenna with a three-way cable. No matter what method we use, it's useless. Increasing the power to 50 watts or 100 watts is useless. This means that it is not even transmitted to the antenna through the feeder. We can only assume that the energy disappears inside the radio station."

"Where did the signal go?" Bai Yang asked, "Did it travel 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 did are still quite rough. It would be best if we could find a radio darkroom to test it."

"Where is the electromagnetic darkroom?" Bai Zhen asked.

Zhao Bowen thought for a moment and said, "There should be one in NUST. I'll ask if I can borrow it."

Although it is said that no conclusion can be drawn without further experiments, Zhao Bowen, Bai Zhen and Wang Ning themselves know that if the experimental conditions are changed, the results will probably be the same.

The three adults present did not believe the explanation of trans-dimensional communication, but none of them could explain the inexplicable disappearance of the signal.

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

"Put aside the anechoic chamber for now. Old Zhao, let's talk about when you can borrow one." Bai Zhen said, "The key to the problem is not here. The most important thing is to find out whether BG4MSR really lives in 20 years. This is the core issue."

"It's true." Bai Yang said, "I have verified it."

"We know you've verified it," Zhao Bowen said, "but a single piece of evidence is not enough. The experiment is only meaningful if it can be repeated."

Bai Yang was stunned. "So... you guys are also planning to make a time capsule?"

As expected, things have developed to this point. Bai Yang thought that no one could believe such an absurd fact based on just a few words, so if he wanted them to believe it, he had to let them verify it with their own hands and see it for themselves.

However, Bai Yang had already stepped into the pitfalls of Time Slow Delivery for them. They only needed to cross the river by feeling the stones and copy the practices of their predecessors along the successful path paved by Bai Yang. Compared with Bai Yang who was completely in the dark when he first tried, Uncle Zhao, Uncle Wang and Dad had it much easier.

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

(End of this chapter)