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"Our system has been practiced several times, and the sending and receiving test on the shore has passed."
The communications battalion commander of the base met Li Qiang and Tang Hua.
"The very long-wave antenna starts from Jiaxing and extends 300 kilometers southwest. The end is assumed to be in Huangshan. In fact, the end is also the originating end. The two can be interchanged. FSK frequency offset modulation, when sending and receiving tests on the shore, the extremely long-wave information transmission rate is 20 bits per minute, and the information transmission rate of ultra-long wave is 900 bits per second."
Tang Hua: "Where was the ticker placed during the shore test?"
Battalion Commander: "Near Dalian."
Li Qiang: "In the shore test, there is no seawater barrier between the receiver and the transmitter, the signal-to-noise ratio is good, and the information transmission rate is actually much higher. Of course, the electromagnetic waves near Dalian are relatively dense, and the receiver will be interfered. But all in all, if the shore test If the information transmission rate is 20 bits per minute, then when the submarine is submerged, the information transmission rate is less than a quarter of this figure."
The three of them stood outside the central control room of the base, and when they turned their heads, they could see the huge antenna array erected over a large farmland.
The main antenna has a total length of 2880 meters, that is, two tall high-voltage transmission towers with a length of 2880 meters. The wires strung on the poles are radio antennas—the antennas of this radio station are lying flat.
In addition to the main antenna, there are three short lines perpendicular to the main antenna, which are also composed of wires suspended from high-voltage transmission towers. The entire antenna array seems to have a big "Feng" written on the ground.
If sending ultra-long waves, it is enough to use this antenna array.If extremely long waves are sent, the antenna array is just the head end of the antenna. The main antenna is connected to the transmission line. The transmission line runs from Jiaxing to Hangzhou and then to the high-voltage line from Hangzhou to Nanchang. A few kilometers of mountains, to the top, ok, a 300 kilometers long telegraph antenna.
In other words, this base can send both ultra-long-wave telegrams and extremely-long-wave telegrams.
……
"Boat 304 dived 30 minutes ago," the signalman at the base reported, "the last 15 minutes to prepare."
Li Qiang: "Is Jiaxing's power supply guaranteed to be error-free?"
"The power grid in the Yangtze River Delta has been adjusted, leaving a sufficient power supply margin of 10 megawatts."
It takes 80 minutes for the submarine to dive to a depth of 45 meters and get ready to receive reports. Li Qiang and the battalion commander are looking at their watches for the countdown.
桌上的地图是本次通信演练潜艇所处的位置——大约在大连东南50公里的海中，离岸不远。因为黄海在这一带的最大水深也就110~120米，所以304艇没法下潜到100米深度来做测试。
However, the test results of 80 meters are also very good.
When the time is up, the central control room sends a telegram.
The more than 2000-meter-long antenna array outside the window seemed to emit a faint "buzzing" sound, and the birds that had been parked on the wires fluttered into flight.Tang Hua even felt that the trees in the distance began to have fallen leaves.
The buzzing has been going on and on—this transmission will last at least 10 minutes, and the photoelectric bill will cost a lot of money.
After sending the report, it fell into a long wait.If the submarine receives the extremely long-wave telegram and accurately identifies the content of the message, it will float up according to the regulations and send the message through the medium-wave radio station, so that the extremely long-wave base will know whether the communication is successful.
In the Yellow Sea, which is 870 kilometers away in a straight line, the first R-class conventional submarine assembled and built by our country, 304, has its bow raised and rises rapidly at an elevation angle of 10 degrees.
The bow of the submarine came out of the water first with a clatter, making a lot of white waves, and then the rest of the hull came out of the water.
"Patrol aircraft reported that boat 304 has surfaced..."
The patrol plane circling in the test area first discovered that the submarine had surfaced. "Boat 304 returns!"
The reported message was decrypted with a decryption machine and printed out as a note. The three of them glanced at the note and knew that the experiment was successful.
……
On February 2, it was still Jiaxing, on the shore of Taihu Lake.
"Let me take a look at the second black technology that Lao Li tinkered with... Ah, I am familiar with this."
Li Qiang: "Four billboards were pasted on the illegal building."
Tang Hua: "It's four tiles."
Shigeru Makino: "Your analogies are very appropriate, but I still like to use the name 'Type 308 Shipborne Phased Array Radar'."
On a flat and open space on the shore of Taihu Lake, a mysterious building about 20 meters high (six floors) was built. The general shape of the building is like an irregular pagoda with eight walls.On each of the four walls, there is an ugly tile or billboard.
This is not the Aegis AN/SPY-1 radar.Nor is it the SFAR phased-array radar suite on the nuclear-powered cruiser USS Long Beach.
Probably... a mixture of the two.Official name: Type 308 Multifunctional Shipborne Phased Array Radar.
"In December last year, the United States started construction of a nuclear-powered cruiser. It was so big that American newspapers and media blew it up," Tang Hua said. "We can't make this nuclear power system for the time being, so let the United States take the lead. But The Pentagon said that this nuclear-powered cruiser is equipped with what is known as the strongest ship-borne radar on the earth, and I disagree with that."
"Their radar was designed in 1955." Li Qiang roughly read the radar's intelligence briefing. "It's unlucky. The control array radar, horizontal phase scanning and vertical frequency scanning, is the same as our 308, but it is a radar with vacuum tube as the core device, hehe."
Tang Hua: "Let's talk about it in the basement of the building. The radiation from the radar is not small."
……
"Target 1, distance 439, height 7700." "Distance 438, height 7700." "Distance 437, height 7600."
The basement is also the radar control center on the simulated ship. For the health of the testers, steel plates were added to the six walls of the basement, and a Faraday cage was made to shield electromagnetic radiation.
After the radar was turned on, the first test was a Tu-4 bomber flying from a distance.This is a large air target. The 308 radar’s theoretical detection range for it should be 480 kilometers. When the plane flew to 470 kilometers during the test, the screen began to display.
"Distance 437, altitude 7600."
Li Qiang: "The data is not correct. The bomber crew kept in touch with us by radio. Their flight altitude was at 7200 meters, and they were slowly descending to 7100 meters."
Tang Hua: "Aha, the altimetry system has a fixed error of 500 meters?"
"At a distance of more than 400 kilometers, the error of the altimetry system may be 600 to 1000 meters. Now it has not exceeded the expected number, but the number reported by dozens of consecutive scans is not more than 500 meters. It seems that Then we can analyze the cause of the error again." Li Qiang asked the accompanying secretary to write down this item.
"Maximum scan frequency test."
The biggest difference between planar phased array radar and mechanical scanning radar is that it can scan very quickly.The mechanical scanning radar is not good, the larger the radar is, the slower the scanning is, and if the large radar rotates once every two seconds, the motor and the rotating disk will smoke in a short time.Even if there is no smoke, it is extremely troublesome to cause mechanical wear and errors due to rotation.
After starting the maximum frequency scan test, the 308 radar accelerated from 6 seconds/360 degrees to 2 seconds/360 degrees, and the original "di,, di,, di" became "di-di-di-di...".
The data refresh frequency is tripled, and the radar operator's mouth can't report in time-in fact, Tang Hua thinks that the authentic combat system should not use voice reports-everyone crowded to the side of the radar screen to look at the image parameters that popped up one after another.
Well, there is still a 500-meter error. In the image displayed by the radar, the altitude of the aircraft is always 500 meters higher than the actual altitude of the aircraft.If it is high and low, that's all right, it means that this is a normal error of the altimetry system.Steady 500 meters short...that's problematic.
As for where the problem lies, let Hangzhou and Nanjing slowly analyze it.
"I used to think that the 307 radar was the king of information control in sea and air battles, but the 308 radar greatly surpassed its predecessors." Shigeru Makino rubbed his chin, "How much do you attach importance to the information acquisition ability and battlefield control ability of battleships? It is beyond any previous era, but perhaps this is the characteristic of the country's thinking."
"This is not a Chinese characteristic," Tang Hua said with a smile, "This is the inevitable direction for the future evolution of maritime battlefields and even all battlefields."
Makino Shigeru's research on this aspect is not so deep, but his intuition feels that this direction of development is very interesting.
"Minister Tang, after five years in China, I am finally back in the design field of large surface ships, which really makes me very excited."
"Makino-san."
Tang Hua took a step closer, lowered his voice and said quietly:
"I saw your design plan for a large surface ship... Do you want to revive the Kaohsiung class in the Chinese Navy?"
Chapter 174, The March 3 Front Moves Northward
The model name and ship class of the large surface ship that has completed the preliminary design have not yet been determined, but it is actually a guided missile cruiser.