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

Seventy-two hours.

For three days and three nights, the exhaust system never stopped.

For the first 24 hours, the exhaust is performed at low temperature. At room temperature, the mechanical pump and diffusion pump remove most of the gas molecules from the pipe, and the vacuum level drops from atmospheric pressure to 10 to the power of negative 5 Torr.

The second 24-hour heating begins, with the outer heating element slowly pushing the shell temperature from room temperature to 350 degrees Celsius, forcing out water molecules, carbon dioxide, and various impurity gases adsorbed on the glass and metal inner walls.

The reading on the vacuum gauge initially rose, but then dropped again due to the continued effect of the high-temperature baking.

The last 24 hours are the critical high-temperature degassing stage.

The temperature was pushed up to 450 degrees and maintained. All surfaces inside the tube that could release gas were thoroughly cleaned at this temperature, and the vacuum level eventually stabilized at 3 x 10 -7 Torr.

The shifts are rotated. Old Sun takes the first half of the night shift, Xiao Zhao takes the second half, Da Liu keeps an eye on the temperature controller and vacuum gauge during the day, and Jiang Ming checks the data every four hours.

At 9 p.m. on the third night, when Jiang Ming entered the confidential cubicle, there were already four people surrounding the exhaust vent.

Old Sun stood on the right side of the exhaust platform, his hand resting on the heating belt control knob.

Xiao Zhao squatted in front of the vacuum gauge, his eyes almost touching the dial.

Fang Xudong sat at the workbench, a sheet of draft paper covered with calculations spread out in front of him. The cables for the frequency meter and power meter were already connected, just waiting for the final power-on.

Da Liu stood guard at the door, clutching a handful of cotton yarn in his hand, unsure of what to do, yet unwilling to leave.

"What is the vacuum level?" Jiang Ming asked.

"Three point one times ten to the power of negative seven," Xiao Zhao recited without turning his head. "It hasn't changed since six o'clock in the afternoon."

Jiang Ming walked to the exhaust platform, bent down to look at the pointer position of the vacuum gauge, and then looked up at the reading of the thermocouple outside the tube shell.

450 degrees, it's stable.

"The tubes can be sealed now."

After Lao Sun turned off the power to the heating element and waited for the casing to cool down to below 200 degrees Celsius, Jiang Ming picked up the high-frequency induction heater and aimed it at the glass neck at the base of the exhaust pipe.

After the glass neck was heated to its softening point, he gently pulled it with tweezers. Under the influence of gravity and surface tension, the glass contracted and sealed itself, eventually forming a smooth, round head.

The moment the exhaust pipe is disconnected, the magnetron becomes a completely sealed vacuum device.

From this moment on, the vacuum inside the pipe is maintained by itself and no longer depends on external pump sets.

It took another two hours to cool down. Only after the tube shell temperature dropped to room temperature did Jiang Ming remove the magnetron from the exhaust platform, holding it in his hands as if he were holding a piece of porcelain.

At midnight, all testing equipment was in place.

The magnetron is fixed on the test fixture, the anode is connected to the sealed absorption load through the waveguide flange, the cathode lead is connected to the high voltage modulation power supply, and the electromagnets are installed on both sides of the tube body with the magnetic pole faces aligned with the axis of the anode resonant cavity.

Jiang Ming did a final check on all the wiring, running his fingers along each cable from beginning to end to confirm that there were no loose connections or misalignments.

"The electromagnet is energized first."

Old Sun turned off the electromagnet's power switch, adjusted the current knob, and inserted the gaussmeter probe on the table into the center of the magnetic pole gap, with the reading starting to climb from zero.

0.05 Tesla, 0.08 Tesla, 0.10 Tesla, 0.12 Tesla, 0.15 Tesla.

"0.15 Tesla, that's it." Old Sun loosened the knob.

Jiang Ming turned to Xiao Zhao.

"high pressure."

Xiao Zhao stood up, walked to the high-voltage control power supply, placed his hand on the switch handle, and glanced back at Jiang Ming.

Jiang Ming nodded.

The sound of the switch being turned on was crisp, like the snapping of a dry twig.

The voltmeter pointer started to spin, climbing from zero to 1,000 volts, 3,000 volts, 5,000 volts, 8,000 volts, and 10,000 volts.

12,000 volts.

The pointer stopped.

All eyes turned simultaneously to the sealed absorption load at the waveguide output.

Nothing happened.

The cubicle was so quiet that you could hear the sound of the diffusion pump cooling water flowing through the copper pipes.

Just when Jiang Ming thought that the magnetic field still needed to be fine-tuned, a glimmer of light suddenly appeared in the observation window on the load side.

The light was faint, blue, like the cold light shining from a distant window on a winter night.

The light did not disappear; instead, it became increasingly stable, spreading from a single point into a uniform glow that illuminated the space behind the observation window as a deep blue.

That is visible light produced by microwave ionization of residual molecules in the air. This phenomenon only occurs when high-power microwaves pass through the waveguide.

The pointer of the frequency meter jumped once, then jumped again, and then began to swing violently, sweeping back and forth on the scale three or four times. Finally, it seemed to be pressed down by an invisible hand, stopping firmly in one position.

2.952 gigahertz.

Fang Xudong stood up from his chair, walked to the frequency meter, bent down and leaned close to the dial, pressing his fingers against the frame as if afraid he might have misread it.

On the power meter, Xiao Zhao's voice had changed.

"1.25 kilowatts! Peak power 1.25 kilowatts!"

Jiang Ming glanced at the clock, noted the time, and then did nothing but stand there, looking at the blue light.

Thirty minutes.

He made the pipe work continuously for thirty minutes.

The pointer of the intermediate frequency meter deflected twice, each time by no more than half of the smallest scale division, before returning to its original position on its own.

The frequency drift is less than five parts per million.

Thirty minutes later, Jiang Ming reached out and turned off the high-voltage power supply.

The blue light disappeared, the frequency meter pointer returned to zero, and the power meter reading dropped.

The confidential cubicle was quiet for a while.

Then, Old Sun clenched his fist and punched his thigh hard, his voice twice as loud as usual.

"We did it! We made it!"

Fang Xudong had already taken off his glasses and was wiping the lenses repeatedly with his sleeve. He put them back on after wiping them several times, but his eyes behind the lenses were still red.

Xiao Zhao squatted next to the power meter, his hands covering his face, his shoulders shaking, unable to utter a single word.

Da Liu squeezed in through the door at some point, standing at the very back with his mouth agape and the cotton yarn in his hand lying on the ground without him picking it up.

Jiang Ming looked down at the quiet magnetron on the test fixture. The tube shell still had light yellow oxidation marks left after the exhaust baking. Its appearance was rough and far less shiny and neat than the captured Soviet-made tubes.

But it is alive.

It just emitted microwaves at 2.952 gigahertz, with a power of 1.25 kilowatts, and operated continuously for 30 minutes.

On this land, in this confidential room converted from a power distribution room, a group of people with no experience in making multi-cavity magnetrons, using domestically produced oxygen-free copper, cerium oxide electrophoretic cathodes, and hand-scraped eight-cavity anodes, accomplished this for the first time.

Deep within Jiang Ming's mind, a gentle light silently bloomed.

In the "Networking Records" database, Old Sun's name card changed from gold to shimmering gold, with visible light patterns flowing along the edges, as if someone had used a red-hot needle to trace new characters on the paper.

Trust Level: A Bond of Life and Death.

He didn't make a sound, but simply raised his head and glanced at Old Sun.

Old Sun was laughing, his face crinkling with wrinkles, and the wetness in the corner of his eye shone brightly in the light.

This level-six fitter followed him, starting from the first failed exhaust of a type B tube, scraping the anode, guarding the exhaust, modifying the annealing furnace, and turning the eccentric hole of the indexing plate. All the most tiring, dirtiest, and most inconspicuous jobs were done by Lao Sun's hands first.

A pact of life and death.

These four words are fitting.

Suddenly, a piercing ringing sound rang out outside the cubicle. It wasn't a telephone ring, but a hand-cranked alarm bell used by the factory security, ringing rapidly and frequently.

Everyone turned to look at the doorway at the same time.

Before the bell had even stopped ringing, the crew-cut officer had already appeared in the doorway, his cotton hat askew, his expression a mix of panic and urgency. He stumbled as he stepped in, nearly bumping into the corner of the worktable.

"Engineer Jiang, Director Wang wants you to go to the South Gate immediately!"