Republic of China: Ace Pilot

Chapter 179, Section 178: Wireless Eavesdropping Equipment, Vienna Eavesdropping on the Japanese
"The device I need should not require any wires, and preferably be very small and not easily noticed."

Fang Wen regretted making that request as soon as he did.

This requirement is too demanding. In this day and age, there are no miniature batteries, no circuits and chips for small devices, and no sophisticated sound receiving, conversion, or radio wave transmission equipment. How could it possibly be achieved?

Just as he was about to cancel the mission, he saw Bai Zeshan deep in thought, so he decided not to disturb him.

A few minutes later, Bai Zeshan replied:

“I have an idea, but it’s rather complicated. The general manager might not understand it just by talking about it, so I need to write it down.”

Unexpectedly, Bai Zeshan actually had an idea, and Fang Wen naturally agreed.

After writing furiously for a while, Bai Zeshan wrote down his design ideas, which Fang Wen picked up and looked at.

The device described by Bai Zeshan is a simplified version of a typical radio broadcasting system.

The entire process from sound wave reception to radio wave transmission clearly demonstrates the basic principles of broadcasting technology.

It consists of 4 components.

1. Sound wave reception
Function: This part is mainly responsible for capturing sound waves (i.e., sound) in the surrounding environment and converting them into electrical signals. This is achieved through an acoustic-electric transducer, most commonly a broadcast microphone.

The diaphragm inside the microphone vibrates with the sound waves, thereby changing its internal electrical parameters (such as resistance, capacitance, or electromagnetic induction), and thus generating an electrical signal corresponding to the sound waves.

2. Signal Processing
Function: The processing stage receives weak electrical signals from the microphone and amplifies and filters them through circuitry containing vacuum tubes.

3. Signal modulation
Function: Modulation is the process of combining an audio signal (i.e., a processed electrical signal) with a high-frequency carrier signal so that the signal can be effectively transmitted via radio waves. In broadcasting systems, commonly used modulation methods are amplitude modulation (AM) and frequency modulation (FM). AM superimposes the amplitude changes of the audio signal onto the amplitude of the carrier signal, while FM changes the frequency of the carrier signal to reflect the changes in the audio signal. The modulated signal contains audio information but is in the high-frequency range, making it suitable for transmission through an antenna.

4. Radio wave transmission
Function: The transmitting section uses an RF amplifier to further amplify the modulated high-frequency signal to a sufficient power level, and then radiates it into the surrounding space through an antenna. An antenna is a device that converts electrical signals into electromagnetic waves and radiates them into the air. The transmitted radio waves carry audio information, which can be received by a distant radio and reproduced as the original sound.

If that's all there is to it, it would at most be a simple radio station, which wouldn't meet Fang Wen's requirements.

Bai Zeshan made a change.

He drew on Fang Wen's logic circuit theory.

A method for remotely stimulating a remote device was designed.

In other words, as long as a signal of a specific frequency is transmitted, the logic circuit of the vacuum tube will be turned on after the remote device receives it.

When it is necessary to stop, a shutdown signal of a specific frequency is sent, and the vacuum tube circuit group will be shut down.

This has a similar ingenious use to the adder that Fang Wen originally proposed.

Even if remote on/off switching, as well as the reception, processing, and transmission of sound waves are achieved, there are still other problems.

The integration of equipment makes it smaller and easier to conceal.

And how do we solve the power supply issue?

If these two problems can be solved, Fang Wen's wireless eavesdropping device will become a reality.

In response, Bai Zeshan proposed his solution.

Equipment integration fixes and reduces functionality to a single, undifferentiated state.

It has only one specific frequency and discards the unnecessary functions of radio broadcasting, leaving only the sound wave transmission and reception and the intermediate conversion process.

This will significantly reduce the size of the device.

The power source for this device is the best available Yongbei brand lighting battery.

A total of four spare batteries provide power, enabling the device to be turned on three times and run continuously for 2 hours.

After reviewing Bai Zeshan's design concept.

Fang Wen was impressed by his bold and imaginative ideas.

In the era before semiconductors, he used vacuum tubes to perform relatively complex logic circuit operations.

In any case, we need to get them to make a physical product first.

Subsequently, Fang Wen gave Bai Zeshan a sum of money to put his plan into practice.

With a definite design concept and readily available components, production is quite fast.

Bai Zeshan disassembled different devices, including broadcasting and radio equipment, put the internal parts back together, and then installed batteries.

And it was done.

Fang Wen didn't expect it to be done so quickly, and he and Bai Zeshan conducted a test.

The device consists of two parts: one is a sound wave receiver and transmitter disguised as a suitcase, and the other is a radio for eavesdropping on specific frequencies.

The eavesdropping radio can be installed in a car or carried around. It has only two operating parts: an eavesdropping switch and an earpiece.

The experiment began with Fang Wen having Bai Zeshan place the briefcase at the feet of the unsuspecting Lin Shuiwang before leaving.

Hundreds of meters away in his car, Fang Wen switched on the eavesdropping radio and put on his headphones.

A moment later, sound came through the headphones.

"Bai Zeshan, what's in this box?"

The sound is clear; the test was successful.

Fang Wen was overjoyed.

Although the device still weighs 30 kilograms, it is disguised as a suitcase, which provides a certain degree of concealment. If operated well, it can be a powerful eavesdropping device.

This technology must not have existed during World War II, so it had to be kept secret, otherwise it would be a huge problem if the Japanese got their hands on it.

He spoke with Bai Zeshan alone.

"Bai Zeshan, what is your opinion of the Japanese?"

"These barbarians from the East have only received a little enlightenment, yet they dare to usurp the host's position," Bai Zeshan said disdainfully.

Fang Wen nodded: "You've seen this device too. I plan to use it against the Japanese. Remember, it must not be leaked. If the Japanese get their hands on this, China will have no secrets left."

Bai Zeshan's expression changed. He suddenly realized what the Japanese might do with this equipment, and if that were the case, he would be a great sinner.

So he nodded seriously: "General Manager, don't worry, I will never tell anyone else about this except you."

"That's good. This secret was known only to the two of us before the Japanese were driven away."

Fang Wen and Bai Zeshan swore an oath by high-five.

Having unexpectedly acquired wireless eavesdropping equipment, Fang Wen felt he could use it to disrupt the business between Mitsubishi and Junkers.

But now we must first find the whereabouts of the Mitsubishi representatives who came to Europe for negotiations, and where they will be holding talks.

There is someone who can help with this.

Fang Wen spoke with Indiana, who was waiting to board his plane back to Tehran.

He was very serious: "I have received information that the Mitsubishi Group of Japan has sent people to Europe to discuss cooperation with Junkers. I must stop them, otherwise heavy bombers will appear over China."

Indiana saw Fang Wen with this expression for the first time, and he could understand the other man's emotions.

"Whatever you want, I will do my best to help you."

This is the result of investing in Indiana, Fang Wen stated his requirements.

This is not difficult. Indiana is a member of the U.S. overseas intelligence network and is the head of the Tehran station. He has certain powers to exchange information with friendly intelligence organizations.

Without involving their own interests, he obtained information about Mitsubishi's whereabouts in Europe.

"The Mitsubishi representatives are in Vienna. They will be holding talks there. After all, the Weimar Republic is still bound by the treaties of World War I, and some transactions cannot be conducted domestically."

After hearing the intelligence from Indiana, Fang Wen decided that regardless of success or failure, he had to try in Vienna.

The Boeing 247 took off from Paris, traveled 1000 kilometers, and arrived over Vienna.

Vienna below is bustling with activity, with dense crowds gathering in the streets.

"What are they doing?" Lin Shuiwang asked, puzzled.

“The Nazi Party has spread to Austria; they are the Nazi Party of Austria,” Indiana explained.

"Why? They're not even from the same country." Lin Shuiwang still didn't understand. "Because they're both Germanic," Indiana continued to explain.

Fang Wen then turned on his radio and spoke with Vienna Airport.

This was his first official landing at the country's airport. The last time, he had secretly landed at a farm outside the city, but unfortunately, all the Weimar officers who could contact the farm had died, so this was the only way he could get there.

After a series of calls, the other party granted permission for the plane to land.

As soon as the plane landed, ground staff came over, and Indiana communicated with them, paying a considerable fee to get through.

The plane can only stay for two days. After two days, it has to leave regardless of whether the business has been completed or not.

In order to find the people from Mitsubishi as soon as possible, Fang Wen and his two companions took an airport taxi to the city.

After the Vienna taxi entered the city, before even reaching its destination, a surging crowd appeared ahead, and it looked like it was about to be surrounded by people.

The driver was terrified and whispered, "You can get out of the car. I won't charge you the fare."

Fang Wen and the other two got out of the car, which immediately turned around and drove away.

The surging crowd, chanting slogans, engulfed the three.

"Move aside," Fang Wen only managed to shout.

The three were separated by the crowd, but they all squeezed towards the side of the street and finally managed to get away after reaching the side of the street.

After searching for each other, they found that they were in different places: Fang Wen was on one side, while Indiana and Lin Shuiwang were on the other side of the street.

After waiting for half an hour, the crowd finally thinned out, and Indiana and Lin Shuiwang quickly came over to meet up.

"Are the things still there?" Fang Wen asked.

"Yes," Lin Shuiwang replied.

This time, Indiana was brought here so that the local intelligence network could be of help, but Fang Wen did not intend to tell Indiana about the wireless eavesdropping device.

Indiana didn't ask any further questions, but instead began to lead the way.

Having worked in intelligence in Europe for a long time, he was very familiar with Vienna and easily led the Mitsubishi representative to the hotel where the representative was staying.

A man was sitting in the hotel with a newspaper, seemingly waiting for someone.

Indiana walked over, and the two didn't seem to interact much. After a while, he came back.

"The registered names are Noguchi Sawakichi and Iwashita Hisaburo."

"Just two people?" Fang Wen asked.

"Yes, they've been here for two days. The people I hired started watching them last night, but they haven't found any contact between them and anyone."

Just as Fang Wen and Indiana were talking, Lin Shuiwang whispered, "Two people are coming over, is it them?"

Fang Wen looked at it.

The two were of East Asian appearance, not very tall, and had bowlegs; these two features were quite obvious.

Fang Wen asked in a low voice, "Indiana, which room are they staying in?"

“705,” Indiana replied.

"Go and keep an eye on these two. If they come back, come to 705 in advance to let them know."

"Ah."

Indiana went out with two Japanese men.

Fang Wenze and Lin Shuiwang went to the front desk to book a room and went upstairs.

Instead of the floor they had booked, they went to the 7th floor.

There, the corridors were empty, and there was no need to worry about surveillance cameras.

Lin Shuiwang took out two iron wires and stirred them in the keyhole.

Fang Wenze, carrying two boxes, blocked Lin Shuiwang's path, keeping watch on him.

Picking locks isn't easy.

Especially for a novice like Lin Shuiwang, beads of sweat appeared on his forehead, but he still couldn't open the lock.

"Don't worry, we have time," Fang Wen reassured him.

"Hmm." Lin Shuiwang felt slightly relieved and continued operating.

Just then, a couple walked over; they were probably residents from the same floor.

However, due to their inability to recognize Asian faces, they mistook them for guests, politely greeted them, and then walked past.

Fang Wen smiled but didn't respond, which was considered a perfunctory response.

The unlocking continued, and finally, with a click, the lock opened.

Lin Shuiwang was about to push the door open and enter, but Fang Wen stopped him.

He recalled that in spy movies, spies would place traps on doors, such as a strand of hair or a rope. If these traps were broken or disturbed, they could arouse suspicion.

Fang Wen carefully examined the crack in the door from top to bottom, and he actually found it.

It was a strip of cloth, one end of which was tied to the chair leg behind the door, and the other end was tied to the doorknob.

Opening the door so abruptly might knock over the chair, and there might be other design elements involved.

Fang Wen carefully pushed the door open, and after it opened to a certain extent, he moved the chair away.

Only then did I go inside.

Room 705.

Two beds, a table, a chair, and another chair that the Japanese placed at the door as a mechanism.

The room was clean and tidy, and there was nothing there.

Wait a minute, when Japanese people come to discuss business, do they bring nothing with them?

They didn't seem to have brought much with them when they went out.

Fang Wen looked around at the room's layout.

Lin Shuiwang lay down on the ground and looked under the bed.

"General Manager, there's something downstairs."

He pulled the things out from under the bed.

It is a box.

Moreover, it was a combination lock, and forcibly breaking the combination lock would alert the two Japanese men, so Fang Wen gave up the idea of ​​opening the box.

He told Lin Shuiwang to put the box back somewhere far away while he went to find a place to hide things.

Under the bed is out of the question; the first thing the Japanese do when they come back is check under the bed.

Where should the eavesdropping device be placed?

The suitcase isn't particularly big, but it's not small either.

He looked at the bedside table.

By the way, there's a gap behind the bedside table, which is just the right size to insert the box.

Fang Wen carefully placed the box behind the bedside table and immediately called Lin Shuiwang to go out.

Then he pulled the chair back to its original position before closing the door.

After doing all this, the two went downstairs, opened the door to their room on the 6th floor, and then went downstairs to wait for Indiana to return.

(End of this chapter)