New York has high incomes and high taxes. Many wealthy New Yorkers have their companies in New York, but their houses are bought in states around New York, such as New Jersey.

The small town of Princeton has a beautiful environment, low taxes, and many wealthy people's houses are located in Princeton, so when Americans mention Princeton, they say that it is the backyard of American high society.

Many ordinary people in New Jersey also travel between New Jersey and New York. New York houses are expensive, land taxes are expensive, and it is common for New Jerseyians to work in New York and buy a house in their hometown of New Jersey.

This has also led to a large influx of New Jersey labor into New York, resulting in a shortage of local New Jersey workers.

What Li Kangping means is to recruit more New Jerseyians who work in New York, encourage them to build a beautiful home in New Jersey, and at the same time promote the development of the local economy in New Jersey.

Jack and other engineers have begun to make engineering drawings for the microphone.

Li Kangping personally made the engineering design drawings of the tape recorder.

Input Signal - Signal Input Part - Recording Head - Pitch Pitch Counter Head - Pitch Output Part – Pitch Feed Signal...... Li Kangping carefully drafted.

The tape recorder designed by Li Kangping has two functions, one is the sound recording function, and the other is the sound output function.

The analog tape recorder has a recording bias equalizer amplifier, which can produce an ultra-high frequency signal superimposed on the audio signal, which can make the sound signal less distorted and improve the signal-to-noise ratio. Once the recording medium is linearized by the high-frequency bias method, the technical quality of the recording signal is greatly improved.

On the analog tape recorder, the recording tape first passes through the trowel head, and then the high-frequency bias current erases the original signal on the tape, and then reaches the recording head, and the audio signal is superimposed on the high-frequency bias magnetic signal, and is recorded on the tape by the recording head, completing the sound recording process.

The above is the design idea of the recorder recording function.

In order to fully embody this design idea, it is necessary to draw engineering drawings detailed to each component, with engineering design specifications.

The fixed operation process of engineering drawing is placed here, and Li Kangping knows every technical detail very well, and it takes a lot of time for him to depict all the technical details in engineering language. And that's just the engineering of the recorder's recording capabilities.

"I have a lot of ideas, but only one pair of hands. Looks like we still need help. ”

Li Kangping stopped his drawing work and paced in a makeshift workshop in Brooklyn.

The temporary workshop for the research and development of film equipment is divided into two areas, the drawing area and the processing and manufacturing area.

Jack, Andrew, and other engineers rolled up their sleeves and worked at the drafting table in the drawing area.

The manufacturing area is quiet, and the engineers have not yet finished their drawings, so they have not yet begun to process and manufacture microphone prototypes.

A few days ago, the sound film equipment R&D team recruited a new engineer, counting Li Kangping, the current team member is 12 people.

"Jack, go out for a cigarette." Li Kangping called Jack to come outside the workshop.

"Dr. Li, I know what you're thinking, you want to recruit more engineers." Jack said.

"Jack, as you can see, with the number of people we have now, the progress of research and development is very slow. Xidian or something may have developed a new recording equipment! ”

"It's possible."

"Jack, you have to remember a point in time, 1927."

"Dr. Lee, I know what you mean, in 1927, Edison's patent protection for sound film technology expired."

"We work backwards to 1927, and in 1926, the film artists used improved sound film equipment to shoot the more mature sound film of the sound film year. In order to help artists shoot sound films, we need to develop all the sound film equipment by the latest month. So, Jack, there's not much time left for us. ”

"It's really challenging." Jack finished one cigarette and then smoked a second cigarette, saying, "Now that we've set the volume, what we're going to do is add enough people to get there in the shortest amount of time." George, who was a college classmate of mine, and he was now working in technology at an electrical company in Michigan, I called George and he was willing to come and work with us, and I thought George was the right person. ”

Li Kangping asked: "How many suitable technicians like George do you know?" ”

"Three, five? Oh, and counting Gordon, that's six. ”

"Call them all!"

"I'll try to do that."

"Jack, you know, my technical director of the Sound Film Equipment R&D project is temporary, and I want you to take my place."

"Dr. Li, do you really think so?"

"It's true. Regarding the R&D project of sound and film equipment, it should be subdivided into several professional groups, such as pickup equipment group, recording/sound return equipment group, editing equipment group, cinema sound return group, and general group. In addition to engineers, we also need to recruit some mechanics who can read drawings. We need a lot of people anyway, and you, Jack, should work in the direction of the technical director. ”

After smoking, Li Kangping and Jack returned to the workshop.

"The pickup equipment is now in charge of Andrew, Jack, you and I work on the engineering of the recording/reproduction equipment."

Li Kangping taught Jack how to design recording/reproducing equipment.

“…… This is the engineering design of the sound recording function of the recorder. Next, I will tell you the design idea of the voice recorder sound output function. On an analog tape recorder, when the recording medium passes through the capsule, it causes a change in the magnetic field, which causes the coil on the capsule to induce a weak current signal, and this current signal is amplified enough to be heard from the speaker or headphones......"

Lee Kangping hopes that Jack will progress to the position of technical director, but at this time, Jack's task is to be a good engineer for recording/reproducing equipment.

Li Kangping explained the design ideas and details of the recording/reproduction equipment while drawing pictures. Jack watched and learned.

Such detailed engineering design teaching takes a lot of time and effort.

But Li Kangping has no better way now, he can only do this.

I'll tell you about the technical ideas that are directional, and you have the ability to carry out specific technical work on your own – this kind of technical talent is extremely valuable. However, Li Kangping's sound film equipment research and development team temporarily lacked this kind of core technical personnel, so Li Kangping had to work hard, and he personally trained the core technical personnel of sound film equipment research and development.