We Live In Nanjing

  Chapter 69 The Wisdom of Uncles

  In the following weekend, Bai Zhen and Wang Ning began to design a remote communication system.

  To put it plainly, it is to let BG4MSR use mobile phones.

  This is very important.

  The immediacy and convenience of mobile phones are much higher than those of fixed phones. It is time to upgrade the girl’s communication methods.

   "The technical logic is very clear, it is not difficult to do." Wang Ning sat on the sofa, rubbing the beard and scum chin, "Basically, we only need to do one..."

   "Relay." Bai Zhen sat opposite him.

   "Yes, we only need one relay." Wang Ning nodded.

  The so-called relay is an extremely common and commonly used infrastructure in amateur radio.

As we all know, there are more people playing UV wave than short wave these years. To play UV wave, you only need to spend a hundred dollars on Taobao Jingdong to buy a mobile phone. This thing is not much bigger than a mobile phone. It is small and exquisite, easy to carry, and comes with a flashlight. The flashlight can also blind your dog's eyes by pressing the button twice. It does not require a heavy and awkward base station like shortwave-but the UV band has advantages and disadvantages. Both UHF and VHF frequencies are much higher than shortwave. You only need to learn physics in middle school. Know that the higher the frequency, the shorter the wavelength; the shorter the wavelength, the weaker the ability to bypass obstacles.

  So the radio waves in the UV band travel through the line of sight. The UV waves can only reach the place where your eyes can see. If there is an obstacle in the middle, the signal will be shielded.

  It cannot reflect through the ionosphere like short waves.

  There are high-rise buildings everywhere in modern cities, and the buildings are stacked on top of each other. Obstacles are everywhere. How can people who play UV band communicate in long distance?

  So people wondered-how about putting a transponder up high.

This retransmission system can be placed on high towers, mountain tops, or even satellites-it must be set up at a high place that everyone can see-the UV band hand station in the hands of HAM, and the signal is sent to the retransmission first. Device, and then forward it through the latter’s hands.

  The transponder stands high and can see far away, and can spread the signal to very far places. Amateur satellites or the International Space Station are in orbits hundreds of kilometers high, and they can even support intercontinental communication.

  Such a forwarding system is called a repeater.

  "Relay?" Bai Yang was confused, he didn't understand how to use the repeater to establish remote control, "how to do it?"

   "Xiao Yang, let you design. If you want BG4MSR to contact us at a long distance, what do you want to do?" Wang Ning asked him back.

   Bai Yang was stunned for a moment, thinking for a few seconds.

  "Uh...a radio communication link should be established so that the size...BG4MSR can transmit the signal to Icom725 over a long distance, and then let 725 transmit it to us."

   "Yes, the idea is correct." Wang Ning agreed, "But what should I do?"

  "She should have a portable mobile phone in her hand as a terminal for sending and receiving information." Bai Yang further imagined, "She sends the signal to Icom725 through the mobile phone, and then Icom725..."

  Here, Bai Yang suddenly got stuck.

"Forward."

  He realized that the role of 725 in the entire link was forwarding, and the girl’s hand station transmitted the signal to 725, and 725 forwarded the signal to Baiyang.

  What should be done to make 725 a forwarding node?

  Icom725, all functions of an old antique like Icom725 have to be realized manually. You have to press and hold the button on the hand microphone to send a call, and release the button on the hand microphone to receive a call. How to remotely operate this one-click operation?

  You are not a robot, you can run for thousands of miles, and you can leave one hand in the room and press the button specially.

"You can't do it with 725 alone." Bai Yang said slowly, "You definitely need a peripheral device. On the one hand, this peripheral can send and receive radio waves by itself, and on the other hand, it can control the 725's transmission and reception. When there is information to be sent, it It controls the 725 radio station to enter the sending state. When there is information to receive, it controls the 725 radio station to enter the receiving state."

  "Savvy, savvy, Xiao Yang." Wang Ning smiled, "As you think, we just need such a peripheral device."

   "This peripheral is a relay." Dad said.

"Yes, it's a relay." Wang Ning nodded, "Xiao Yang, do you know the structure and working principle of a repeater? That kind of pure analog repeater... We'd better use a pure analog repeater, digital Relay or digital-analog relay is a bit complicated. I'm afraid that the girl over there can't handle it, and I'm afraid that the too sophisticated things won't last too long. The structure of analog relay is so simple that you can DIY it with two walkie-talkies."

"Because the basic structure of a repeater station is that two amateur radio stations are put together back to back." Old Bai took his words and explained to Bai Yang, "The main component of a repeater is two base stations with a duplexer. , If you use two independent antennas, the duplexer can be saved. Its operation is very simple. There are two base stations, one for receiving signals and the other for transmitting signals..."

  Lao Bai pointed to his son.

"For example, you are a mobile station and I am a relay. Talking to me is equivalent to sending a signal to me. My ears are the receiver and my mouth is the transmitter. I am composed of these two stations. Yes, when my ears hear what you say, I will relay your words to Lao Wang with my mouth, and when Lao Wang speaks to me, I can also relay what Lao Wang said to you, understand?"

  White Yang nodded thoughtfully.

  "I can understand this, but why can it be remotely controlled?"

  "The key is here. Didn't you just say that you need a peripheral device, can that peripheral device automatically control the 725's sending and receiving?" Wang Ning said, "It just so happens that the repeater runs automatically, and it is usually unattended."

   "Some relay stations are on the top of the mountain, some are on high towers, and some are on the satellite." Bai Zhen said, "So most of the relay stations are unmanned."

"This means that it has a mechanism for automatically switching between sending and receiving." Wang Ning picked up the oil-based pen on the sofa and set up the small white board on his thigh. "What we need is this mechanism, and use it to replace human hands to operate the 725. 'S send button, look at Xiao Yang."

  As he said, he drew a rectangular box on the whiteboard, and drew two flat rectangles on the box.

  Write three small characters "receiver" in the small rectangle on the top, and "transmitter" on the bottom.

  Finally use an arc to connect the two rectangles together.

  "This is a relay."

  Wang Ning pointed to the large rectangle with an oil-based pen.

  "It consists of two radio stations."

  Wang Ning pointed to the two small rectangles inside with an oil-based pen.

"Usually, once the upper receiver receives a signal, it will trigger to turn on the lower transmitter, and the transmitter will forward the signal, but if we take this relay apart and connect the receiver and transmitter to 725 respectively superior……"

  Wang Ning drew another box next to the repeater.

  Then mark 725 in the box.

  Remove the arc again, disconnect the two small boxes in the repeater, and connect them with the 725 in a straight line.

"So at this time, once the above receiver receives the signal, it is no longer the transmitter, but the 725 that is triggered to turn on again-understand? The communication link will be like this: BG4MSR uses the signal Send it to the receiver, the receiver controls 725 to enter the sending state, and 725 transmits the signal to us over time."

   "Then we send a signal to the past?" Bai Yang asked.

"That's the reverse reproduction of this process!" Wang Ning replied, "We transmitted the signal to her 725 over time and time. 725 received the signal and triggered the start of the transmitter below, which sent the signal to the BG4MSR mobile station. "

  Finally, with a big stroke, he drew a big circle to frame everything in.

   "The above is the basic logic of the entire link!"

When Bai Yang stared at the picture on the whiteboard for a long time, and then looked at Wang Ning's hairless head, the latter seemed to be shining with wisdom.

"impressive."

  "In this process, the role played by 725 is no longer a mere radio station." Dad said, "It's a hyperspace antenna."

  The technical logic has been sorted out.

  The next step is to make a plan.

"First of all, we have to determine the goal of the plan, and first determine what effect we want to achieve." Wang Ning picked up the oil-based pen on the sofa and turned the small white board over. He raised his head and looked at Lao Bai, "First The point is remote control, right?"

"Yes, remote control." Bai Zhen nodded, "Even if MSR doesn't stay in front of the two or five, not sitting on a chair, but in the next room, outside the house, or even several kilometers or more than ten kilometers away. Normal communication with this side, this is the effect we want to achieve."

  "What are the specific operational requirements?"

  "It is best to achieve the same effect as the normal use of the mobile phone." Bai Zhen replied, "Holding the mobile phone in her hand, she can talk by pressing PTT."

   "Okay, the requirements are as follows... First, separate the platform and remote control, and second, simple operation and easy learning." Wang Ning nodded, and wrote down one by one on the whiteboard.

   "Also... there is one more." Bai Yang raised his hand.

   "Say Xiao Yang."

  "Cannot cause damage or destruction to the radio station itself." Bai Yang reminded.

This is very important. No matter what Dad and Uncle Wang want to do, it cannot affect the Icom725 radio station itself. They have not yet understood why this radio station has the ability to communicate over time. For everyone, the old abductee. Five is a black box, in this case, it is the wisest choice not to touch it.

  Bai Zhen Wang Ning Zhao Bowen recklessly dismantled the camera once and opened the shell of the radio station. Fortunately, it did not cause any impact.

   "Okay...Thirdly, it should not affect the normal operation of the radio station itself." Wang Ning wrote down.

  Finally, he raised the whiteboard so that everyone else could see it.

  The handwriting is sloppy but eye-catching.

  First, separation of human and platform, remote control!

  Secondly, the operation is simple and easy to learn!

  Thirdly, it should not affect the normal operation of the radio station itself!

The above three items will be the framework that they must follow when advancing the plan. They will do their best to upgrade the communication tools in the hands of BG4MSR. When the team of experts of the emergency communication headquarters of the amateur radio emergency communication headquarters is fully operational when reversing the future to save the world, The wisdom of the uncles will be invincible!

  (End of this chapter)