A nation's industrial development begins with junior engineers.

Chapter 916 One force can defeat all methods!

The test has begun.

The tent was filled with the low hum of various devices. The indicator lights on the single-board computer flashed rhythmically, the pen tip of the pen plotter drew fine lines on the graph paper, and the open-reel tape recorder rotated slowly.

At first, everything seemed to be going according to plan. The 1 kHz test signal from the standard signal generator passed smoothly through Jiangxia's "solid" solder joints, displaying a clear sine wave on the oscilloscope. The background noise signal transmitted back by the hydrophone array was also faithfully recorded by the recorder.

"Signal path normal! Background noise acquisition begins!" the technician in charge of monitoring reported.

Teacher Shih-E breathed a slight sigh of relief, while Teacher Xu-Hua kept a close eye on the various instrument parameters.

However, when Professor Xu Hua tried to switch the signal source to simulate more complex low-frequency pulse signals and hoped to conduct preliminary analysis through the preprocessing unit of the captured "early tide" system, problems arose.

Although the indicator lights of the disassembled pre-signal processor were on, when its output was connected to the single-board computer, the signal displayed on the screen became a jumbled mess of waveform glitches, making it impossible to identify any useful features.

"This……"

"As expected, let's wait and see if the pre-installed program in the single-board computer can perform active matching!"

However, after a few minutes, the baseline on the oscilloscope screen, apart from a slight, imperceptible jitter due to ambient electrical noise, was like a stagnant pool, with almost no meaningful signal waveform.

The connected pen recorder, with its suspended ink pen, could only draw an almost straight line on the paper tape.

"No! The signal is completely distorted!"

Professor Shih-E frowned, adjusted several parameters, but the result remained the same.

He then tried to have the system perform a simple background noise spectrum analysis, one of the most basic self-test functions of underwater acoustic equipment. The result was a chaotic data stream from the single-board computer; none of the expected frequency peaks appeared, and instead, a large amount of erroneous data, suspected to be caused by computational overflow, appeared in some irrelevant frequency bands.

Well, the technological barriers are thicker than expected.

Just as Jiang Xia was scratching his head, thinking about whether he should try to use a single-board computer to simulate some basic signal injection systems and reverse-engineer their functions.

A commotion arose outside the tent.

The tent flap was suddenly flung open, bringing with it a chilly sea breeze. Old Wang, with a strange expression that mixed with disdain and smugness, stretched out his large hand in front of everyone.

In his rough palm lay several small cylinders tightly rolled with waterproof oil paper, their size and shape indeed somewhat resembling... well, sheep droppings.

"Didn't I tell you to find the cassette tape? Where did you find these shit balls?"

Without wasting any words, Lao Wang placed the oil paper package on the workbench and carefully opened it. What was revealed inside stunned both Jiang Xia and Teacher Shi E, who had been full of anticipation.

They are strips of brown magnetic medium directly wound onto miniature plastic cores!

The magnetic tape had a metallic sheen on its surface, was not protected by an outer casing, and appeared extremely fragile. Moreover, its width and thickness were significantly smaller than those of the computer magnetic tapes commonly found in China at the time!

"Where... is the cassette tape casing?" Jiang Xia poked it twice with his hand and looked up to ask Lao Wang.

"Hmph," Old Wang snorted, "That old fox is really cunning! He took all the tapes out of the cassette and rolled them up like this, saying... to reduce weight and make them easier to hide! That's what they looked like when we found them."

"Hey, where is he hiding?"

"You don't want to know..."

"Oh~"

Hearing that Lao Wang refused to answer, Jiang Xia assumed that Lao Wang had gone to great lengths. Upon hearing this, he rubbed his chin and began to consider how to extract the data from the tape.

Junichiro was truly ingenious. Removing the protective casing was not only to reduce the size and make it easier to hide, but also because there was no standard cassette or guide zone markings, so ordinary tape drives could not automatically identify the starting position of this special type of tape.

But machines can't do it, but people can!

All you need to know is the basic principle of magnetic tape manufacturing.

When you play with cassette tapes, have you noticed that most cassette tapes use transparent or semi-transparent polystyrene cores?

There is a 5-10 mm transparent leader 2-3 cm from the innermost circle. This is the "physical initiation". After the leader, the color suddenly darkens.

The darker areas are actually the brown-black magnetic powder layer, and the boundary is easily identifiable.

So everyone watched as the boy with the ahoge (cowlick) carefully began fiddling with the cassette tape, trying to find the transparent part. The others crowded around behind him, helping him search for the transparent part in his mouth.

Only Lao Wang and Zhao Gang kept a little distance, their expressions strange.

Ok?

No!

Holy crap, is the notebook made of all-black ABS?

but it does not matter!

As long as you understand the principle, that's enough!

Just look at the side of the tape with your naked eye! The lead-in area will appear slightly thinner because there is no magnetic powder. Under light, it will show a slight "step". Simply scratch the side of the tape with your fingernail. The first "smooth area" you encounter is the starting point!

Hmph, no matter how cunning you are, as long as you understand the principle, you won't be able to jump around!

However, as Lao Wang and Zhao Gang watched Jiang Xia, whose face was extremely close to the tape for easier observation, Lao Wang struck Er Kang's classic pose...

Suddenly, Old Wang leaned forward, forcefully extending his right arm toward Jiang Xia and the tape, his palm taut and his fingers spread wide, as if trying to grasp something firmly from afar.

Finally, the five fingers curled up a few more times in vain.

"Brother...you...don't get too close..."

……

Jiang Xia picked up a cassette tape and looked at it over and over. He found that although the tape base was wide, the track arrangement was standard. It was just that the outer casing was missing, so it could not be fixed into the reader.

This is really difficult for top-tier junk collectors?

"Do you have cardboard, scissors, glue, and thin wire?"

"Yes! If Xiao Jiang wants it, I'll dissolve it for you right away!"

Dissolve?

Jiang Xia turned her head and watched as a researcher took some yellow particles out of his toolbox.

Oh... fish maw...

Of course, it's fish glue. People live off the land and water, and being near Dalian, we naturally use fish glue.

Don't ask why we don't use white glue or epoxy resin glue. The former is still undergoing a 5-ton pilot test at the Sijiucheng Organic Chemical Plant and may not be available on the market until next year.

As for the latter, you won't find it on the market anymore. Even the Navy's supply has been drastically reduced, with the electronics factories taking over the entire supply...

Jiang Xia quickly cut a piece of cardboard, rolled it into a cylinder the same thickness as a regular cassette tape casing, carefully wrapped the high-capacity cassette tape around it, and then made two small clips with thin wire to secure the ends of the tape.

Yes, this kid's recklessness has returned.

He planned to bypass all automatic identification and protection mechanisms and manually "feed" the reader this special tape.