Li Weidong has been a temporary worker in the chemical materials sales department for three years, and he can find the materials he needs with his eyes closed.

Chalcocite, capacitance (2200 picomethod), high impedance headphones, 2AP9 diodes, 1N60 diodes, enameled wires, wires, variable capacitors...

In just five minutes, Li Weidong walked out with a bamboo basket full of materials.

At this time, Hu Guangliang and the three of them had already paid and were sitting at the small table against the wall of the store.

In addition to the three of them, there were also four or five young people who looked like college students.

Although Li Weidong did not know their names, he also knew that they were all radio enthusiasts.

Making ore machines is a very niche and very compelling hobby, just like playing racing cars in later generations to participate in the Haitian feast.

In the same way, there is a need for communication between enthusiasts.

The side room of the chemical materials store has a few tables and also provides tea, which is the best place for communication.

Those young people knew Hu Guangliang's thoughts and offered suggestions one after another.

"Materials, making ore machines, materials are very important, Lao Hu, don't you save money."

"I heard that my buddy from the Ordnance Institute said that the Q value of the 222 air variable capacitor produced by the military aircraft can reach 15,000, and if you build one, you will definitely be able to charge two more radio stations."

"That is, the materials of the chemical materials store department are all Datong Road goods, so it is better to go to the laboratory of the Ordnance Institute."

...

It was a young man who said this.

Li Weidong also knew him, but he didn't know his name.

I only know that the big guys call him Lao Bai.

Dressed all day long, wearing a small military hat, cowhide coaxing.

If in the past, Li Weidong heard this, he smiled faintly.

You don't mess around in the sales department, he can save some effort.

Not today.

...

"The performance of air variable capacitors is not necessarily better than that of small sealed variable capacitors."

This unreasonable remark echoed in everyone's ears like a thunderbolt.

They turned their heads together, only to see a young man carrying a bamboo basket standing there quietly, although the young man was wearing a shabby cotton jacket, there was a heroic spirit that was difficult to hide.

The first to react was Hu Guangliang.

He stood up, with a happy face, walked over and gave Li Weidong a punch: "Weidong, you wore a torn cotton jacket today, I didn't recognize it just now."

Where have you been going these days, I haven't seen you several times, and I thought you weren't working in the store department. ”

They are all young people and love to be lively.

Every time he made a mining machine, Li Weidong was always watching from the side.

Over time, he is also half a radio amateur.

Although he has no practical hands and weak theoretical knowledge, he is far more familiar with various materials than these enthusiasts.

In the past, the materials that Hu Guangliang needed were named for Li Weidong to choose.

"It's true that I'm quitting, isn't it missing a few brothers." Li Weidong grinned.

The two exchanged pleasantries for a while, but the general next to them was not happy.

"Weidong, people who play mining machines know that the quality and performance of different variable capacitors are different. A small, hermetically sealed variable capacitor performs worse than an air variable capacitor, which is determined by the principle by which they are made. ”

Hu Guangliang also said: "It's not that my buddy doesn't give you face today, but what you said has violated scientific principles." If in the past, I would have used these materials improvised, but if I can't do it today, I will return them. ”

Li Weidong stopped in front of Hu Guangliang at a wrong step: "Practice brings true knowledge, why don't we test it?" ”

The proposal was immediately embraced.

"It's a good idea, we use capacitors a lot, but we never test their Q value."

"Wei Dong is an honest man, although his education level is not high, he knows more about ore machines than me."

"That is, which Q value is high, you can find out if you test it."

...

"Okay, let's test it out." Hu Guang nodded.

He also wanted to know exactly what the Q value of a small, hermetically sealed variable capacitor could be.

"You wait, I'll get the test tools."

Li Weidong put the bamboo basket on the table, turned around and walked towards Niu Dahong.

"Sister Niu, here's the thing..."

After listening to Li Weidong's narration, Niu Dahong, who was knitting a sweater, frowned.

"I don't understand the things you said, what tools are needed to test that, and my sister will give you a bill. Don't let these boys return the goods, otherwise, it will be troublesome to reconcile with the finance department at the end of the month. ”

"Don't worry, with me, not only will they not be able to return the goods, but they will have to buy them again." Li Weidong took the order and entered the warehouse.

Five minutes later, he walked out with a fist-sized copper coil in his hand, a frequency tester, and several patent copper wires.

Hu Guangliang has already put the variable capacitor on the table.

Li Weidong walked to the table and looked at everyone: "I use the coil and the variable capacitor in parallel as an LC loop to detect the Q value of the coil, because the coil is used as a fixed value here, the Q value will also change when measured in parallel with different immutable capacitors, and the performance of the variable capacitor is indirectly measured." ”

"Do you have any objections to this method?"

Hu Guang nodded: "No!" ”

Lao Bai nodded: "No!" ”

Everyone nodded: "No!" ”

Li Weidong quickly connected the coil and finally connected it to the frequency meter.

The moment it was connected, the dark blue screen of the frequency meter lit up.

The line of numbers that appeared on it made everyone gasp.

“23000！”

"My God, look, there are 23,000, which is much higher than the air level of the military plane."

"Impossible, absolutely impossible, this is not scientific!" Lao Bai looked incredulous, raised his head suddenly, and looked at Li Weidong.

"Did you do it?"

Is this unaffordable?

Li Weidong frowned, and was about to speak, but was stopped by Hu Guangliang.

"Lao Bai, you don't know who Wei Dong is, how can you make trouble? Besides, whether to sell this variable capacitor today or not, what does it have to do with Weidong? ”

Lao Bai was speechless.

However, he is a master who does not give up until the Yellow River.

I picked up the frequency tester again and tested it again, looking at the dazzling 23000 on it, and then I had to accept this result.

"Brother Weidong, tell your brother, why is this thing unscientific?"

Everyone also gathered around, and it was incredible that the performance of an old-fashioned variable container could surpass that of the latest air variable capacitor.

Li Weidong smiled faintly and picked up the capacitor: "You are all college students, you have studied physics, and you often do experiments, you should know that there is a phenomenon called error in physics."

In principle, air-variable capacitors perform better than hermetically sealed variable capacitors.

But.

The cleanliness of the variable capacitor, the spacing inside the capacitor, and the degree of oxidation can make the capacitor and the envisioned capacitor have a large error.

Air capacitors are new products, and the process is generally not as mature as the old products. ”

After speaking, Li Weidong looked around at everyone: "So, this is very scientific." ”