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Chapter 237 MIT Radio Association Project

After lunch, everyone else had something to leave, only Lin Hong was left to follow Wu Fei to the MIT Radio Association, and Zhang Xin also had something to do in the afternoon, she said that she was already familiar with the MIT Radio Association. Pen ~ Fun ~ Pavilion www.biquge.info Church

They simply couldn't understand why Lin Hong and Wu Fei were so obsessed with radio.

As Wu Fei walked, he introduced some things about the MIT Radio Association to Lin Hong.

"The call sign of the MIT Radio Association is X, and this is the collective call sign. The association was founded very early, dating back to 1909, and is the oldest university amateur radio station in the United States. At that time, China had not yet begun the Xinhai Revolution. ”

It has to be said that since that time, China has lagged behind the West too much in these aspects.

"The members of the association are mainly MIT students, teachers, and staff."

Wu Fei and Lin Hong came to the X radio room of the Massachusetts Institute of Technology, which is located in room 358 on the third floor of this building, with a total of two radio operation areas. In addition to the Radio Association, in fact in MIT, there is an organization that is very closely related to it, called the MITUHF Relay Association, which has a call sign on the top floor of the Greenbuilding, the highest building in IT, where there is a good view, very conducive to weak signal communication in the UV band......"

Wu Fei introduced everything related to radio in MIT to Lin Hong in detail.

Because today is the weekend, there are not many people in the whole building, Lin Hong didn't meet a few on the road, but when passing through the corridor, through the cracks in the doors of some rooms, you can occasionally see that some people in the room are occasionally busy with their own things.

Some are performing mathematical formulas on the blackboard, while others are experimenting in the laboratory.

They came to an area of room 358 on the third floor.

Lin Hong was completely attracted by the equipment placed in this area, and he found that compared to the equipment here, the equipment he had seen before was scum, and this was the artifact-level equipment used in ham!

"It's a Ten-Tecorion and Ten-Tecorion-II professional radio!" Lin Hong sighed. Templar

The Massachusetts Institute of Technology is rich, and these two devices are the best devices in amateur radio equipment, and even reach the professional level, and it is a bit too extravagant to use them for amateur wireless communication.

"yes. In fact, these two equipment have only been updated for a long time, this is the No. 1 operation area, and the old equipment has been placed in the 357 workshop next door. Wu Fei introduced, "These two devices are each equipped with a set of kilowatt-level power amplifiers, and the two sets of equipment can work at the same time. The antennas include a set of HF directional antennas and a full-size dipole antenna in the 160m band. ”

In addition to these devices, computers are also indispensable.

With the development of computers, the connection between radio and computer is getting closer and closer, and the computer has been assisting radio communication from the beginning, and even has a tendency to be the main equipment.

It's so luxurious, it's too extravagant!

After listening to Wu Fei's introduction, Lin Hong sighed again and again, and at the same time felt a little itchy in his heart, seeing such luxurious equipment, he was really a little moved, and he hadn't touched the radio for a long time.

"Can I try it out?" Lin Hong asked a little embarrassedly, "I'm ashamed to say that it's the first time I've seen such a high-end equipment." ”

"Absolutely." Wu Fei said, helping to start the power of the radio station.

Lin Hong put on headphones and started to tune in to monitor the signal on the amateur band.

Although he had never used such luxurious and advanced equipment, the principle of radio had not changed, frequency modulation and amplitude modulation were always indispensable, and Lin Hong could see how it was used from the words on the knob.

Listening to the familiar rustling sound in the headphones, Lin Hong had a knowing smile on his face.

It's been a long time since I've felt this feeling.

Lin Hong entered the novice channel, established communication with several novices, and went offline after pointing out a few of their basic ham knowledge.

"I haven't used the radio station for a long time, and I'm a little rusty. Lin Hong said with a smile, "I'm ashamed to say that this kind of high-end goods is the first time I use it." ”

"I see you're very easy to use, even the professionally trained check-in staff isn't as skilled as you. Are you really using it for the first time? Wu Fei had been observing Lin Hong's operation of the radio station all the time, and found that his operation was neat, the frequency modulation was accurate, and he was very sophisticated. I secretly praised in my heart, and I really deserved to be the champion of CQWW.

"Yes, the radio station I used to use was still an amateur radio station left by Riben Ham back then, although it has been so long, but I repaired it, and it is still quite easy to use, and I used that radio station to compete."

"Cow!" Wu Fei gave Lin Hong a thumbs up, he had to admire, the other party actually won the championship with an antique-level radio station, he simply didn't have any words to describe his mood.

Work area 2 has a Yaesuft-2000 equipment and an amplifier.

Next door to the radio room, room 357, is a small museum of X, which houses some old components and radio equipment, and all the old equipment that was replaced before has also been moved here.

It's old, but it's still working, but unfortunately, these devices are now piled up in the corners and dusty.

When Lin Hong saw these devices, he was a little saliva. There is even an urge to buy them all back.

But then he gave up, the equipment was too much space, and if he moved it all back, his room would be full.

After all, he is in someone else's house, and there are still many inconveniences.

In this workshop, Lin Hong also saw some strange equipment.

The equipment seemed to be a complete set, mounted on a shelf that could be pushed, with computers and several devices that Lin Hong had never seen before.

On this shelf, there were several pieces of manuscript paper, which attracted Lin Hong's attention. 、

He took a closer look and found that some data was densely recorded on the manuscript paper.

"What kind of device is this?" Lin Hong asked curiously.

Wu Fei was helping to sort out some scattered documents, he looked back and replied:

"This is the portable ground equipment for our school's GNSS monitoring station."

When it was over, he asked, "GNSS, you know, right?" ”

Lin Hong shook his head: "I haven't heard of it." ”

This is the abbreviation of globalnavigationsatellitesystem, which translates into Chinese as global navigation satellite system. At present, there are two main parts, one is the GPS system of the United States, and the other is the GLONASS developed by the Soviet Union. ”

Lin Hong nodded slightly, this thing sounds really high-end, it involves satellite communication.

"Several members of our association, led by a professor, are working on a project to try to decipher the GPS and GLONASS channel coding chip sequences with this equipment to see if there is such a possibility. Once the cracking is successful, a prototype can be developed according to the coding rules to obtain and track the signals of the Soviet navigation satellites. ”

Wu Fei is also a member of this project team, so he knows more about this matter.

Lin Hong was fascinated by what he heard.

He asked, "What antennas do you use to get satellite signals?" ”

He has studied the technical manual of mobile phones, of course, he knows that the signal transmitted from the satellite is attenuated very much after the long journey, and the power of the antenna on the earth is basically only 10 to the minus 16 watt level, if you want to receive these signals accurately, the general antenna can not complete this task.

Wu Fei gave Lin Hong an admiring look, because the question asked by the other party was directly asked on the key, this is "as soon as the expert makes a move, he will know if there is one".

"The antenna we use is a butterfly antenna for the monitoring station, with a radius of 1.8 meters, which can amplify the received signal more than 300 times."

Another artifact!

This antenna is simply too powerful.

Lin Hong can be sure that this antenna is definitely not the exclusive equipment of their association, but is used by MIT for scientific research.

It's cool to do research in MIT, and you can even use this level of equipment!

However, Lin Hong still felt strange, even if the satellite signal was amplified more than 300 times, the signal was still too weak to be at the level.

However, Wu Fei was a little unclear about this, and just told Lin Hong that this was related to the coding method of satellite communication, and through special coding, the weak signal could be amplified from the algorithm, and he didn't know how to do it.

At the heart of the ground equipment, the shelf in the workshop, is Agilent's 89600 vector signal analysis system, which is used to analyze the RF signal in depth with its dedicated VXI bus test equipment.

It's a long experience.

Lin Hong found that compared to them, the things he had done on the radio station before were simply worthless.

It's really a mountain that is higher than a mountain, and if you don't compare, you will never know how big the world really is.

Lin Hong really felt that the knowledge he had mastered was too little, and there were too many things to learn.

He secretly decided that he was going to stay at MIT for the upcoming summer vacation, either to read in the library or to hang out behind the students and learn something. Anyway, he had heard for a long time that the management of MIT was very free, and it was allowed to occasionally go to the professor's class to observe.

Lin Hong saw that there were still some manuscript papers on the shelf, which were hung next to the shelves with folders, Lin Hong wanted to pick them up and take a look, but he was worried that it was a little abrupt.

At this time, Wu Fei suddenly said: "You take a look here now, I'll go to the toilet." ”

"Okay."

When Wu Fei walked out of the room, Lin Hong immediately picked up the manuscript paper on the shelf and looked at it.

It was all the data recorded by observation, and Lin Hong couldn't understand it at all, but he subconsciously used his powerful memory to memorize these data in his brain.

The manuscript paper was flipping rapidly, and Lin Hong's brain was also running rapidly at the moment, almost reaching the realm of ten lines at a glance.