-
Add Bookmark | Recommend this book | Back to the book page | My bookshelf | Mobile Reading
Free Web Novel,Novel online - All in hlnovel.com -> Sci-fi -> We live in Nanjing Text Chapter Thirty-Five Radio 3P
Previous page Return to Catalog Next page
- Friday.
Ban Xia hummed a song and spread out the drawings on the table.
The drawings given by bg4mxh detail the modification points of the gr3188 repeater and icom725. Last night, bg4mxh patiently and slowly guided the same as teaching kindergarten children to recognize Chinese pinyin, so that Pinellia understands the functions of each interface. , repeat a sentence three times, repeat it three times if you don't understand, move with emotion, understand with reason, earnestly and kindly seduce, and lure and annihilate, the girl is also very serious in learning, the one who keeps the teacher but is shelved The English-Chinese dictionary was taken down, and I looked it up if I had anything to do.
In the afternoon of late autumn, the weather is rarely dry, the window sills are covered with bird droppings, and the road is covered with golden fallen leaves.
The temperature is getting cooler day by day, and when the girl sees more and more squirrels in the community, she knows that another winter is coming, but there is no snow in Nanjing in winter, and the small animals have not had time to adapt to the climate change in the future. They're still getting ready to store for winter, and the dense winter fur that these little rodents have spent millions of years evolving will keep them awake in the heat this winter.
It used to snow in Nanjing, but since a certain year, it has stopped snowing.
"cor outthe motorola receiver cor out of the repeater is connected to the ptt of the radio station."
"rx audio, where is the rx audio interface? Here it is connected to the mic interface of the radio station."
"The last is gnd."
Ban Xia was wearing a vest and shorts, her hair was tied into a ponytail, and she was sitting cross-legged on a chair. The table in front of her was full of electronic parts.
She pulled out the hand microphone of the icom725 radio station, and moved closer to her eyes curiously to observe carefully.
It is the first time for Pinellia to pull out this thing. It is also icom's hand microphone. It is the same brand as the radio station. It is heavy and made of thick materials. It is just the size of a palm when you hold it. I don't know how long it took. There is a small number pad, the numbers have been blurred.
The plug of the hand microphone is cylindrical. Generally speaking, this cylindrical plug is called aviation plug, and the full name is "aviation plug". It is an eight-hole plug with a small hole in the center, and other small holes are evenly distributed around the outside. , and its socket is in the lower left corner of the radio operation panel, corresponding to the plug, and there are eight slender metal pins in the socket.
Each needle has a different function and function. If Banxia wants to connect the radio station and the relay together, the first link must go from here.
The hand microphone is a microphone, a microphone, and people hold the hand microphone to talk, so under normal circumstances, the information is input into the radio station through the hand microphone jack.
This is the mouth of the station.
The receiver of the repeater station is about to be inserted into the mouth of the station.
As for the transmitter of the repeater station, it must enter the station later.
It is simply a radio 3P.
But Bai Zhen waved his hand: No, it's not a 3P radio station, how could it be so promiscuous? The transmitter of the repeater is not responsible for the output, it is the receiver.
Finally, the receiver can transmit information to the radio station, and the radio station can transmit information to the transmitter link.
So this is Radio Centipede!
In order to find out where the eight pins in the socket lead to, Bai Zhen and Wang Ning searched the entire Internet and found the instruction manual for the icom725 amateur radio station.
"Bg4msr, look carefully at the interface of the hand microphone. These eight pins are numbered from 1 to 8 counterclockwise, and the middle one is number 8. The three interfaces we need are ptt, mic, and It¡¯s gnd.¡± Bai Yang explained carefully, ¡°mic is pin 1, ptt is pin 5, gnd is pin 6 and pin 7, we¡¯re going to use pin 7, do you hear me clearly? over.¡±
No one spoke in the channel.
"Did you hear clearly? over."
No one has spoken in the channel yet.
"Miss? bg4msr? Are you there? Why don't you talk? over."
Bai Yang urged Ban Xia to hurry up, and the latter had no choice but to plug in the microphone again, and said angrily:
"Didn't you ask me to pull out my microphone! How can I talk?"
¡¤ ¡¤
¡¤ ¡¤
¡¤ ¡¤
Pinellia powers up the soldering iron.
Rosin is needed to use an electric soldering iron. Ban Xia searched the computer city but couldn't find it. Bai Zhen had an idea and asked her to rob a musical instrument store, and she found it.
Wang Ning told Pinellia to pay attention to safety when using electric soldering irons.
Do not hold your hands on the iron core.
Bai Zhen said there would be such a fool? Hands on the core of a soldering iron?
Wang Ning said why is it gone? Most of them use soldering irons as pens.
Ban Xia straightened the thin white wire on the repeater, then picked up the scissors, "clicked", and cut off the PCB board at one end neatly.
pcb?bsp; "Let's make do with it, one is enough, and it's not too bad." Bai Zhen shook his head, "With the electromagnetic environment of her era, farts can be heard all over the world."
In theory, all conductors can be antennas.
It's just that the effect is different.
Therefore, to make an antenna, you can get materials from anywhere, such as clothes hangers, golden hoop sticks, Qiankun circles, tight hoop spells, purple gold bowls, nine-toothed nail rakes, Fangtian painted halberds, Qinglong Yanyue knives, as long as you can get your hands on it, there is nothing that cannot be made into an antenna.
Wang Ning and Bai Zhen chose to use coaxial cables.
"Coaxial cable! It's pretty easy to get. There are everywhere in the city. Phone lines, TV lines, and Internet lines will do."
"It's best to look for 75-7, 75-5 is also fine!"
The coaxial cable is easier to find than the Qinglong Yanyue knife and the effect is better. It is often used as the feeder of the antenna. In fact, it can also be used as an antenna. The structure of the coaxial cable is simple. It has a two-layer structure. The center is a metal core. There is also a layer of fine metal mesh shielding layer outside the wire. The space between the core wire and the shielding mesh is filled with insulating material, and the outermost layer is a rubber sheath.
To make a coaxial cable into an antenna, the most important thing is to remove the metal shield.
The shielding layer is like a Faraday cage. The reason why the anti-interference ability of the coaxial cable is stronger than that of the ordinary twisted pair is because of the existence of this layer of shielding network. It can not only isolate external interference, but also prevent the electromagnetic waves generated inside the cable from radiating outward. Diverge, so peel off this layer of skin, and the radio waves can spread out.
"144mhz, how long should it stay?" Wang Ning asked.
Bai Zhen stared at the black cables piled up in circles on the floor, pondered for a few seconds, and did quick mental calculations in his head.
"About 0.5 meters."
The two used a ruler to measure the length of 0.5 meters at the end of the coaxial cable, and then cut a circle with a knife at the position of 0.5 meters.
This is a massive circumcision, the foreskin alone is half a meter long.
They peeled off the 0.5-meter-long foreskin, revealing the inner silver metal shielding net.
Wang Ning and Bai Zhen squatted on the floor, and slowly rubbed the metal shielding net with their hands. With skillful techniques, they loosened the shielding net made of soft metal threads, and then pulled it back bit by bit, like turning over clothes. It fits over the rubber sheath of the coaxial cable like a sleeve.
After the installation is completed, the simple entry-level 144mhz antenna is basically completed.
This coaxial cable is both a feeder and an antenna. The stripped part is the antenna responsible for radiating radio waves, and the unpeeled part is the feeder for transmitting signals.
It's that simple.
Finally, Wang Ning used a standing wave meter to make fine adjustments.
The two carried out nine experiments yesterday with this set of antennas. The soft coaxial cable could not be supported by itself, so Wang Ning tied it to a wooden mop stick. He held up the two mops and leaned out of the window. It seemed that it was about to take off at any time, and the owners who passed by in the community were scared and called the police.
In Nanjing City in 2019, in the Meihuashanzhuang community full of power switches and electric vehicles, these two seemingly simple whip antennas still stubbornly supported the scolding between Wang Ning and Bai Zhen.
"Old Bai, are you fucking done yet? My waist is about to break, and I told you that you have to compensate me for my medical expenses, and five hundred yuan is no less."
"I'll give it to you when you fly down, and I promise to burn it for you. It's a lot of money."
"Fuck you, come up if you have the ability, come up and try."
"Come down if you have the ability!"
"Come up!"
"Come down!"
Banxia tied the finished coaxial cable antenna to the stick, and bg4mxh specifically told her to use insulators.
There are two antennas in total, one for the transmitter and one for the receiver. The girl put a lot of effort into sticking them out from the attic skylight and standing them on the roof.
144mhz is the uv band, to be precise, the vhf band. Electromagnetic waves propagate within the line of sight, so the higher the antenna, the better.
Pinellia asked how far it can travel?
Wang Ning shrugged, he was not sure.
In the conventional concept, uv waves are used for short-distance communication, but there are no certainties, and there are exceptions to everything. As long as the conditions are right, the uv wave band can also communicate hundreds of kilometers in direct frequency.
Bai Zhen said that Nanjing in the doomsday era is empty, and the electromagnetic environment must be very, very quiet, and the signal-to-noise ratio of the communication will be very good.
Wang Ning said that the world with only one person is really trouble-free, and the relay even saves sub-tones, since you are the only one talking anyway.
That night, the girl fully charged the mobile phone.
Baofeng uv5r waterproof version.
According to Bai Zhen Wang Ning's instructions, she went to look for waterproof handstands. Banxia found eighteen well-preserved waterproof handstands on Zhujiang Road, such as Motorola and Yaesu. Shenji Baofeng uv5r can still work normally.
Open the icom725 radio station.
Open the gr3188 analog relay.
Ban Xia took a deep breath, she worked on this for a whole week, success or failure depended on it.
Gently turn the switch knob on the top of the handle, and the LCD screen will light up.
On a night full of bright stars, the girl left the room and climbed up to the attic, sat on the roof, and told bg4mxh about the stars she saw.
</div>A total of 18 well-preserved waterproof handsets were found, such as Motorola, Yaesu, and various big names were defeated. In the end, only the 100-yuan magic machine Baofeng uv5r can still work normally.
Open the icom725 radio station.
Open the gr3188 analog relay.
Ban Xia took a deep breath, she worked on this for a whole week, success or failure depended on it.
Gently turn the switch knob on the top of the handle, and the LCD screen will light up.
On a night full of bright stars, the girl left the room and climbed up to the attic, sat on the roof, and told bg4mxh about the stars she saw.
</div> - 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
- Previous pageCatalogNext page