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

Before the echoes of the three knocks had faded, Wu Hanzhang had already stood up from his chair, placing the enamel teacup he was holding on the corner of the table with a soft thud.

The person standing outside the door was a head taller than the door frame. His gray-blue eyes peeked through the crack in the door first, followed by a dark brown sheepskin hat, and then a thick woolen overcoat, buttoned from the collar all the way to the bottom, with the hem still damp with dew from the yard.

As Ivanov stepped through the door, his left shoulder nearly brushed against the newly hung nameplate above the door frame.

Wu Hanzhang went up to greet him and said "Please come in" in Russian. Ivanov did not respond to this polite remark. His gaze had already passed over Wu Hanzhang's shoulder and landed directly on the ignition test platform at the back of the research room.

In the center of the test bench, Yuanlei No. 1 is fixed on a copper base. The anode shell reflects the light of the incandescent lamp. The permanent magnet clamps on both sides fit the tube shell tightly. The high-voltage coaxial cable is led out from the top and connected to the front end of the oscilloscope and power meter.

On the oscilloscope screen, a stable green waveform is refreshing at a rate of about thirty times per second, with uniform amplitude, no glitches, and no jumps.

The pointer on the power meter stopped at the 1.25 kilowatt mark and remained motionless.

Ivanov walked to the testing platform, stopped, put his hands in his coat pockets without taking them out, and looked down at it for a long time.

Jiang Ming turned around from the soldering station, still clutching a soldering iron in his hand; the tip was already cold.

"Comrade Ivanov, this is our domestically produced magnetron, numbered Yuanlei No. 1." Wu Hanzhang stood to the side of the test bench, pointing to the power meter head, "Peak power 1.25 kilowatts, frequency 2.952 gigahertz, has been running continuously for more than 40 hours, and the frequency drift has always been less than five parts per million."

Ivanov pulled his right hand out of his pocket, tapped the glass panel of the power meter with his index finger, and knocked it with his fingernail, as if to confirm that the pointer was not drawn on.

"Anode material?" he asked, his Russian pronunciation bearing a distinct Leningrad accent.

"The batch of oxygen-free copper you allocated to us," Jiang Ming put down the soldering iron, walked over, and answered in Russian.

Ivanov turned to look at him, his gaze shifting from his face to the row of glass-encased tubes on the workbench behind him.

"What are those?"

"Double-diffused silicon triode, base width 0.48 micrometers, cutoff frequency exceeding 2 gigahertz." Jiang Ming didn't elaborate further, taking a sealed tube from the cotton box and handing it over.

Ivanov took the tube, held it up to the light, and examined it. The tube casing was smaller than a little fingernail, and the three gold-plated pins gleamed in the light.

He returned the pipe, and then did something no one expected.

He took off his hat, the sheepskin fur on the brim curling slightly under the incandescent light. He held the hat in front of his chest with his left hand and let his right hand hang by his side. He bent over deeply towards Jiang Ming, his back almost parallel to the ground, and stood up for a full three seconds.

Wu Hanzhang almost dropped the teacup in his hand.

"Comrade Jiang." Ivanov straightened up, his voice trembling slightly, as if something was stuck deep in his throat and forcibly suppressed. "I must apologize for my previous attitude. At the Shenyang Copper Processing Plant meeting, I judged that it would take you at least five more years before you could possibly get involved in the manufacturing of centimeter-wave devices."

He paused, switched the hat from his left hand to his right, and glanced at the green waveform on the test stand that was still outputting steadily.

"Using nitrogen backflushing to solve the oxygen-free copper-hydrogen problem, using an eccentric indexing plate to process an eight-cavity resonant cavity on a regular lathe, and using double diffusion to create a submicron base without a photolithography machine—these are things that might not be possible to do simultaneously even in the Leningrad laboratory."

Jiang Ming didn't follow up on the bow's sentiment. He only said, "You approved the oxygen-free copper. Without those two tons of raw materials, none of this would have happened."

Ivanov looked at him for a few seconds, then suddenly reached into the inner pocket of his coat and pulled out a palm-sized notebook from its close-fitting position.

The notebook's leather cover was worn shiny, and the corners had curled up and been pressed back down many times. Two threads on the spine had broken off and were temporarily tied up with a thin wire.

He handed the notebook to Jiang Ming, and as he loosened his grip, his fingertips lingered on the cover for a moment.

"This is my personal record of thirty years of actual measurements, from the first day I entered the Leningrad Electrical Engineering Institute in 1924. All the experimental parameters of vacuum induction melting, all the failures and successes of ultra-high vacuum welding are all in here."

Ivanov's voice became calm, as if he had already said the most difficult things to say, and all that was left was to give an explanation.

"This does not fall under the scope of official Soviet technology transfer; it is my private notebook, and I have the right to decide who to give it to."

Wu Hanzhang stepped forward, seemed about to say something but then stopped, ultimately just watching Jiang Ming take the notebook.

The notebook was heavier than expected, with many experimental data strips and photo fragments sandwiched between the pages, making the whole book bulge as if it were stuffed with too much stuff and might fall apart at any moment.

"Thank you, Comrade Ivanov." Jiang Ming held the notebook in his palm, not in a hurry to open it.

Ivanov put his hat back on, pulled down the brim, and turned to face Wu Hanzhang.

"Director Wu, I hope this notebook can help you establish your own high-frequency vacuum tube industrial system, a system that does not depend on anyone else."

Wu Hanzhang reached out and shook hands with Ivanov firmly. After shaking hands, he did not let go, but patted the other's hand.

"I thank you on behalf of everyone in the factory."

Ivanov nodded, turned and walked towards the door. When he reached the door, he glanced back at the green waveform on the test stand, his lips twitched, but he didn't say anything more. He then pushed the door open and went out.

The lab was quiet for a few seconds. Wu Hanzhang looked at the closed door and let out a soft breath.

Jiang Ming then turned to the first page of the notebook.

In the center of the title page, there is a line of Russian text written in blue-black fountain pen ink. The handwriting is more neat than the main text, as if it were an inscription written on purpose.

He read it word by word. The first half of the sentence was an introduction, and the second half was a smelting formula. The formula described the balance between the partial pressure of metal vapor and the adsorption rate of the crucible wall under vacuum induction melting conditions. It involved a correction factor, and the applicable range marked on it just covered the range of copper-tungsten alloy ratios required for high-power pulse tube anodes.

Jiang Ming stared at the formula for a long time, his fingers pressing on the edge of the paper, feeling the slight bumps left by the ink drying on the paper.

This coefficient is exactly the missing piece of the puzzle he needed when he was about to manufacture high-power pulse tubes.

But before he could put this piece of the puzzle into the next round of experiments, another line had already broken in the south of the city.