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

"7.2 degrees, hold on, don't let the main axis drop back."

When Lu Qinghe announced the scale, there was still a hint of doubt in her tone, but the tip of her pencil had already written the direction and angle of elevation on the recording paper.

Old Sun knelt at the bottom of the support, tightened the four bolts diagonally with a socket wrench, and finally knocked the spindle locking pin into the second limit hole.

Fang Xudong threaded the VSWR meter into the feeder, his gaze moving back and forth between the pointer and the antenna main beam.

"The cold standing wave ratio is 1.3, the support is not twisted, and we need to check the hot reflection after powering on."

Jiang Mingsong opened the antenna frame, his shoulder throbbing with a dull, numb pain from the iron pipe digging into it. His right hand had been gripping the wrench for too long, and a small patch of skin had been rubbed raw on his palm.

He walked back to the power supply cabinet and pushed the emergency power cut-off lever back into the working position.

"For the second ignition, first use 30% power to test the reflection, then increase to full power after five seconds."

The diesel generator throttle lever was pushed all the way to the bottom again, and the voltmeter started to climb from zero, stopping when it reached 3,600 volts.

"Low power preparation".

"Field strength meter reset to zero."

"The monitoring frequency is locked at 5.3 MHz."

"Close the switch."

The thyristor lit up with a purple light, and Source Thunder No. 1 sent out the first set of low-power pulses. The pointer of the standing wave meter crossed 1.3 and stopped near 1.4.

Fang Xudong stared for two seconds, then reached out and patted the side panel of the power supply cabinet.

"Hot state 1.4, can be fully upgraded."

Jiang Ming turned the voltage regulating handwheel, and the voltmeter went over 8,000 volts and was pushed back to the 12,000 volt red line.

The brightness of the magnetron cathode increased, the core of the pulse transformer emitted a rhythmic low hum, and the antenna vibrator maintained an elevation angle of 7.2 degrees in the wind.

The field strength meter pointer stopped near its original mark, without the expected change.

Lu Qinghe looked at Jiang Ming.

"The field strength at the local point of the mound is the same as the first time."

"Check the remote feedback."

Half a second later, the field strength meter pointer bounced off to the right.

Fang Xudong, who was in charge of the measurement, thought that the vibration caused the error. He pressed his hand on the instrument casing, but the pointer continued to climb and soon crossed the calibration line.

"The echo at the far end is stronger, exceeding the first 12 decibels; the meter is about to fill up."

He switched to the attenuation setting, the watch hand fell back to the middle, and then moved two increments to the right.

With the same 1.25 kW peak power and the same antenna gain, but by changing the 7.2 degree elevation angle, the scattered signal returning from the mine increased by 16 decibels.

Fang Xudong pulled out the slide rule, but stopped just as his finger reached the propagation loss scale.

This reading cannot be calculated using a conventional planar model.

Two kilometers away, the pulse main lobe sent out by Yuanlei-1 rose upwards after leaving the mound, penetrating the lower edge of the inversion layer, which was more than 60 meters high, before the first sand ridge.

As the cold air near the ground and the warm air above form a refractive index gradient, the beam no longer travels in a straight line, and its propagation trajectory gradually bends downward.

When the main petal crossed the first sand dune, the center height was still forty-one meters.

After passing through the inversion layer, it swept over the second sandbar, and its landing point just covered the upper half of the antenna array outside the mine.

The high-dust-laden air layer left by the dust storm confines the beam to near-Earth space. The environment that was originally responsible for consuming energy now forms a short-lived atmospheric waveguide.

The pulse did not collide with the two sand dunes, nor did it cancel out the reflected waves from the ground.

It travels along a curved path and directly penetrates the enemy's receiving antenna.

The oscilloscope in the mine's listening room first displayed a vertical bright line, indicating that the protection diode would enter reverse breakdown when the second pulse arrived.

The third pulse passes through the already failed protection stage and rushes into the local oscillator coupling port.

The reference signal of tens of milliwatts was covered by repeated pulses of one kilohertz, the phase-locked loop phase detector continuously output erroneous voltages, and the voltage-controlled oscillator rapidly shifted to the edge of the frequency band.

"The reference frequency has drifted!"

The operator grabbed the tuning knob to correct it back, but the numbers on the frequency meter were still fluctuating. It quickly dropped from 5.30 MHz to 5.47 MHz, and then fell to 4.91 MHz.

The technical supervisor pushed aside the operator next to him and directly cut off the automatic frequency sweep, attempting to save the three transmitters in manual mode.

After losing a unified reference, the three power amplifiers each entered free oscillation, their spectra collided with each other, and self-excited spikes appeared continuously in the overlapping region.

A hole appeared in the white noise that had been playing for days in the monitoring headphones on the hill.

Lu Qinghe's hand was on the gain knob, but before he could adjust it, the noise disappeared from the headphones.

There is no gradual weakening process.

One second there is full-scale interference, the next second only the receiver's own thermal noise remains.

The bright band on the oscilloscope breaks off in the middle, shortens at both ends, and the black area in the center of the screen expands outward.

"The 5.3 MHz interference has disappeared."

Lu Qinghe rotated the tuning knob, sweeping through the frequencies from 4.8 to 5.6 MHz segment by segment.

"5.1 MHz is empty, 5.4 MHz is empty, and 4.9 MHz is just background noise. All three transmitters are out of lock."

Fang Xudong still held the slide rule, his thumb resting on the eight-decibel loss mark, his gaze fixed on the elevation angle dial.

Seven o'clock two degrees.

The antenna was pointed at the empty sky, but the field strength received from the direction of the mine was 16 decibels higher than that of the horizontal transmission.

He rechecked the antenna gain and switched the field strength meter back to the attenuation setting, but the reading remained unchanged.

"How did the beam cross the sand dunes?"

"From above."

"Raise it to this angle, and the straight landing point will be one kilometer behind the mine."

"It didn't go in a straight line."

Fang Xudong looked up at the night sky the antenna was pointing to. He couldn't see anything under the starlight, only a layer of newly dispersed dust hanging above the Gobi Desert.

Every mark on the slide rule still holds true, but he had chosen the wrong propagation environment, and the planar model was never qualified to explain this ignition from the beginning.

Lu Qinghe took off her headphones, revealing a red mark on her right ear from the pressure of the earcups, and a strand of her hair fell out from under the pencil.

She first glanced at the tin can sheltered stove that Old Sun had built, then looked at the Yagi antenna that had been raised 7.2 degrees.

The technical team from Beijing did not produce a larger generator, nor did they push Yuanlei-1 beyond its rated power.

Jiang Ming only changed the position of four bolts.

That eight-decibel barrier that blocked all calculations was bypassed by an antenna pointing towards the sky.

Lu Qinghe pressed the walkie-talkie again.

"Tuqiu calling command post: All three enemy frequency sweep transmitters have been lost. The 4.8 to 5.6 MHz band has been restored and is repeating. The jamming zone has been cleared."

The walkie-talkie first crackled with the sound of people running, followed by Director Wang's orders.

"The first battalion will advance towards the north ditch, the second battalion will block the western exit, the artillery company will remain silent, and all units will confirm the resumption of radio communication at each level."

Reports from different numbers began flooding the channel.

"One revenue was received."

"Second revenue secured."

"Communications restored at outpost number four."

"Radar base number three has received a signal from command."

These sounds traveled through sandstorms and gullies, their clarity not great, but they were reconnected to form a complete communication network.

Old Sun took the socket wrench off the bolt and brushed the sand off his knees.

"I told you the pipe wouldn't break."

Fang Xudong finally put away his slide rule and squatted down next to Jiang Ming.

"What is the height of the inversion layer?"

"Around sixty-seven meters."

"You didn't have a weather balloon or an upper-altitude thermometer, so how did you calculate it?"

Jiang Ming picked up a small handful of sand from beside his feet and released it.

The fine sand first floated upwards for a while before being carried away by the crosswind.

"The wind told me."

Fang Xudong stared at the grains of sand, his lips moved twice, but he didn't ask any further questions.

Lu Qinghe put his headset back on and began recording the signal strength of each unit after they had resumed communication.

As soon as she finished writing down the second set of data with her pencil, a faint blue dot appeared on the far right side of the oscilloscope.

The blue dot stayed for less than a second before disappearing into the background noise.

"Wait a moment."

The tuning knob was turned to 5.56 MHz, and a blue dot reappeared on the edge of the screen, this time lasting for three seconds.

Lu Qinghe narrowed the receiving bandwidth, and the blue dot began to move to the left, with each jump being a different distance from the old sequence.

"There is still a signal inside the mine."

Jiang Ming raised his hand to check his watch; exactly twenty seconds had passed since the first interference disappeared.

The next moment, harsh white noise flooded back into the headphones, and the black area on the oscilloscope was quickly filled with a brand new bright band of interference.