I started with a ship full of max-level veterans, and I'm just a complete noob.

The following morning, at the Third Electronics Factory in the suburbs of Beijing, in the factory director's office.

Jiang Ming spread the paper with a sketch of a loop antenna on Director Zhang's desk.

Director Zhang had just picked up his teacup when he put it back down.

"Xiao Jiang, explain yourself clearly, what exactly do you want to do?"

Jiang Ming pointed his finger at the 35-centimeter-diameter copper ring on the sketch, speaking a little faster than usual.

"The pipe is holding back the interference, merely guarding the bottom line, but the other side won't stop."

"Their use of pulse detection to test their location capabilities indicates that they are afraid of being located."

"Even if we can get a rough direction ahead, even if it's only plus or minus 15 degrees, it's better than not being able to find anything at all."

Factory Director Zhang did not respond immediately. His gaze shifted from the sketch to Jiang Ming's face, and then back to the paper.

Director Wang sat in the corner, flipping through the technical points compiled by Jiang Ming, without looking up.

"You work with vacuum tubes."

Factory Director Zhang put the lid on the teacup; the sound wasn't loud, but each word was delivered firmly.

"The task book of the Third Electronics Factory states that it is an anti-jamming military vacuum tube, not a radio detection device."

"You're telling me now that you want to build antennas and do direction finding, do you know that's overstepping your authority?"

Jiang Ming opened his mouth, but before he could say anything, Director Zhang raised his hand and stopped him from speaking.

"I'm not saying your idea is wrong."

"But you need to understand, our factory doesn't even have a proper antenna workshop."

"A loop antenna requires copper tubing, precise bending, shielding gaps, and coaxial cable. Where are you going to get all that stuff from?"

"I'm not going to build a complete direction finding system in the factory."

Jiang Ming suppressed his eagerness and lowered his voice.

"I just want to write a set of usage suggestions to tell the people at the front how to use the existing antennas and receivers to make the most basic direction determination."

After Director Wang finished flipping through those pages, he neatly folded them and placed them on his lap.

"Whom do you intend to send this suggestion to?"

"Send a confidential telegram to the base communications team, to Chen Zhiyuan and his men."

Director Wang took off his glasses and slowly wiped the lenses.

"Xiao Jiang, if what you write is just about how to use the pipe, that's your job."

"But if you write about how to set up the antenna and how to determine its orientation, that's not within the scope of the Third Electronics Factory's responsibilities."

Jiang Ming remained silent for a few seconds.

He knew that Director Wang was right.

In 1955, the boundaries of responsibility between different units were as clear as tofu cut with a knife, and no one could easily cross the line.

"Then let me put it another way."

Jiang Ming took out his pen and began to rewrite the sketch on the back.

"I won't write how to set up the antenna, I'll only write how to use the tube in the direction-finding receiver for the best results."

"As for how they configure the antennas and choose the locations, that's their communications team's business."

Factory Director Zhang turned around, his expression softening slightly.

"Show me what you've written, and I'll have the confidential office review it."

"The wording must not have any commanding tone; it can only be technical advice."

Jiang Ming nodded, put away the sketch, and turned to leave.

"Little Jiang."

Factory Director Zhang called out to him from behind.

"First, establish a firm foothold in the pipeline; the rest will naturally fall into place."

Jiang Ming replied "Understood," then pushed open the door and walked out.

The telegram was sent from the confidential office that afternoon.

Three days later, in the communications room of the Northwest Base.

Chen Zhiyuan read the telegram from Beijing to Lao Zhou and the communications team.

There are three core points.

When using the tube in the direction-finding mixer stage, it is recommended to lower the operating point by 5% to reduce noise.

If used for phase comparison, the two signals must originate from the same source and be recorded simultaneously, with a recording accuracy of no less than milliseconds.

When the aperture of a loop antenna is not less than 30 centimeters, the noise coefficient of the tube can support directional resolution of ±15 degrees.

After listening, Old Zhou lit a cigarette.

"This guy knows the pipe's temperament better than anyone in our communications team. He even figured out what antenna to use for it."

The door to the communications room was pushed open from the outside.

A young female technician entered, wearing a gray-blue overall and with her hair tied up tightly.

Her face bore dry, red marks from being exposed to wind and sand for so long, and she had a notebook tucked under her arm.

"Lu Qinghe, aren't you on duty at the south direction finding point?"

Old Zhou turned to look at her.

"The shift has changed, I'm rushing back to check the telegram."

Lu Qinghe reached for the telegram and read it quickly, his gaze lingering on the third item for a few seconds.

"That's all?"

That's all.

Lu Qinghe put the telegram back on the table and opened the notebook.

Inside was a hand-drawn map of the terrain surrounding the base, with densely packed contour lines and several markers circled in red pencil.

"A directional resolution of plus or minus 15 degrees is sufficient for flat terrain."

She spoke at a steady pace.

"But this isn't flat terrain."

The pencil tip is in a shaded area on the east side of the topographic map.

"This is an extension of the Altun Mountains, with an elevation difference of more than 300 meters."

"Shortwave signals will diffract and reflect when they reach this point."

"In other words, a signal coming from one direction may be split into two directions when it reaches our antenna."

Chen Zhiyuan frowned.

"You mean, single-point orientation measurement can produce false azimuth?"

"It's not a possibility, it's a certainty."

Lu Qinghe closed the notebook.

"I spent forty days at that spot in the south. The clutter azimuth was never fixed, with the largest deviation exceeding thirty degrees."

"That's not a problem with the equipment; the mountain is just bouncing the signal back."

She paused for a moment, her gaze falling on the telegram.

"I don't deny that this engineer in Beijing understands pipes."

"But the third condition he wrote is the ideal condition from the textbook."

"When you get to a place like ours, the 15-degree angle plus the reflection from the mountains means the error more than doubles."

"If you want to do direction finding, you need to set up at least two points, at least 800 meters apart, and record the data at the same time."

"Only when the azimuth lines intersect can we eliminate false peaks caused by reflections."

She drew two intersecting lines in the blank space of the telegram.

"Furthermore, it is necessary to continuously record the changes in signal strength at different times to see which directions are fixed and which directions are drifting."

"What's drifting is reflection."

Old Zhou stubbed out his cigarette and nodded.

She has a point.

"Last month, the orientation was off by 30 degrees. Now that I think about it, it does match the direction of the mountain."

Chen Zhiyuan remained silent for a moment, then put the telegram away.

"I wrote your opinion in my reply and sent it to Beijing."

Lu Qinghe walked to the door, then turned back.

"Don't just write down my opinion."

"Add a sentence at the end of the reply: If that engineer Jiang in Beijing really understands anti-interference, please ask him to first explain how to eliminate the false orientation caused by the reflection of the mountain."

The door closed.

Old Zhou muttered, "This girl has the exact same temper as her master."

Chen Zhiyuan didn't reply, but just lowered his head to write a reply.

When he was writing the last part, he hesitated for a moment, but still copied Lu Qinghe's sentence verbatim.

When Jiang Ming saw that sentence, it was already completely dark in Beijing.

The light from the confidential room shone on the telegram; the handwriting was Chen Zhiyuan's, but the tone was not his.

He folded the telegram, put it in his pocket, and walked out of the confidential room.

The winter night wind blew in from outside the factory wall. Jiang Ming wrapped his coat tighter and stood motionless under the eaves.

Mountain reflection, multipath error, false orientation.

He knew these words; they were in textbooks from later generations.

But when placed in the Gobi Desert in 1955, with no computers, no spectrum analyzers, and only manual recording and pencil calculations, he suddenly realized that he could not come up with a solution that could be implemented on-site.

The things that Lu Qinghe observed while squatting at the direction finding point for forty days are things he could never have imagined sitting in his dormitory in Beijing.

Jiang Ming's lips twitched, revealing a bitter smile.

It's not a pleasant feeling to be questioned to your face.

But she's right.