"Signal enhancement can only be used where the signal can be received, but here is underground. The surrounding reinforced concrete completely shields the communication signal.

No matter how to enhance the communication signal, it is impossible to pass through such a thick wall. Moreover, these concrete walls have steel bars, which completely shield our communication signals. "Sausage shook his head.

"If we can make an antenna and extend it along the ventilation duct to the outside, will we be able to restore the communication signal?" Lin Rui asked again.

"Theoretically, it is possible, but we have to have an antenna of sufficient length, and this must be insulated from the antenna, because the ventilation pipe is a steel tube.

And from our side through the ventilation duct to extend outside, at least ten meters. Where do we find such a long antenna? Sergey shook his head.

Lin Rui walked to the weapon box next to him, opened the box, and took out the magazine from inside. After thinking a little bit, he took out the magazine. Take out the spring in the magazine,

"What do you think of this thing? Can it be used as an antenna?" Lin Rui asked.

"It's too hard. Although it has good elasticity, it is easy to get stuck when passing through the corner of the ventilation duct. It makes it impossible to wear it outside." Sausage looked at it and shook his head.

"Then find other materials, and you can always think of ways to try it. Anyway, it's better than just sitting here and waiting." Lin Rui gestured to them.

"I have an idea. He has a communication command center here, and the communication equipment here also has a fixed antenna, but because the power supply of the equipment is cut off, it cannot be used.

I think we can think of ways to remove certain parts from the communication equipment here and install them. So there may be no matching, but you can change it slightly. Sergey turned around and asked Gonzalez, "What is the size of the ventilation ducts here?" "

"Fifteen centimeters of small ducts. However, there are fans for the fresh air system in the ventilation ducts. It is not an easy task to smoothly pass the antenna through the ventilation ducts." Gonzalez shook his head.

"We have to try, everyone, we start to find something that can be used as an antenna substitute, we need enough length.

What we want is not to pursue a perfect replacement, as long as we can solve the communication problem, send the message, and as long as the brothers outside can receive the message, we will be rescued. Lin Rui clapped his hands, "Come on, let's start." "

The mercenaries began to take down the communication equipment on the line, and their communication equipment had jacks for external antennas.

It is not a big problem to find an alternative antenna, but it is difficult to lengthen it and modify the interface to extend that antenna to the outside.

Passing through the ventilation duct is a very troublesome process. Because of the safety design, the ventilation ducts here are very narrow, with only 15 cm of space.

To send the antenna made by them to the outside, it must be inside the 15-centimeter pipe, and the material requirements are very high by making several turns.

The material must have a certain strength to support the weight of the antenna itself, and be flexible, and must be able to extend into the corner.

After trying several times in a row, Lin Rui found that it was too difficult. They made an antenna that is about fifteen meters in length, but the antenna is too long and there is a problem.

If the antenna cable is too long, the signal attenuation will be great. In this way, even if they extend the antenna outside the ventilation duct, it may be difficult to restore communication.

The sausage was the first to discover this problem. After he explained it to Lin Rui, Lin Rui asked him how to solve it?

Sausage was silent for a while, "The general practice is to add a GPS signal amplifier to a certain cable length to amplify the signal.

Such cables generally use specific types of cables. The attenuation of this type of cable is 0.4DB, the amplification gain of the signal amplifier is 26DB, and the antenna gain is 37DB. Just calculate according to this value.

If signal coverage is required in the basement, it is not enough to have an antenna. Nowadays, signal forwarding systems are used in many places.

But we don’t need this, we just need to restore communication. "

"Well, I'm not a technician in this area. But I want to know, how can I get this **** amplifier?" Lin Rui frowned.

"Signal amplifier." Sausage thought for a while, "This is not complicated. There are a lot of communication equipment here. I can remove some parts from it and see if I can roughly make one."

Sausage and several other mercenaries removed some electronic components from the communication equipment in the room and roughly connected them together.

They do not have soldering equipment such as an electric soldering iron, so they can only use it. The lighter heats and melts the solder, so that these components are assembled together.

Reluctantly made up a very simple signal amplifier.

However, the quality of the antenna has a great influence on the signal, even if a signal amplifier is added, it still does not work.

Because their antennas cannot be fully extended outside, they still cannot receive signals.

"Still not working?" Lin Rui turned his head to look at the sausage.

Sausage adjusted it a bit, and only shook his head, "We still have to try to get the antenna outside."

"Okay. But we've tried many times, and this antenna can't reach the outside at all and got stuck on the second corner." Sergey shook his head.

"Is there any way? For example, through shorter ducts, or ventilation ducts that are easier to pass." Lin Rui turned his head and asked Gonzalez.

"I don't know, I just paid for someone else to get this place, and I didn't design it myself. How do I know where the ventilation ducts are shorter?" Gonzalez shook his head.

"Then start with the direction and location where we came in. We are now in the basement. Above our head is the location of the kitchen of this villa, facing west.

That is to say, the nearest location to the ventilation duct on the outer wall should be there. Lin Rui tried his best to recall the location of this building.

"Yes, the nearest exterior wall should be at that location. We are now using the location closest to the exterior wall." Sergey was a little helpless, "Although there are other ventilation ducts in the fresh air system, I am afraid the location will be further away. "

"No!" Sausage waved his hand suddenly, "The boss reminded me just now. That is the location. After we were locked in, we naturally found the ventilation duct closest to the outer wall and tried.

But I don’t know if you have noticed that this is a hidden basement. It's quite hidden, so you can't see such a large underground space from the outside.

Since concealment was considered when designing and constructing here, we overlooked one point, that is, the ventilation ducts do not directly lead to the outer wall.

So our closest location to the outer wall may not be the shortest and most convenient location. "