Siheyuan: Start with a big car

Chapter 8 It's Science
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, capacitor (2200 picofarads), high impedance earphone, 2AP9 diode, 1N60 diode, enameled wire, lead wire, variable capacitor.
In just 5 minutes, Li Weidong came out with a bamboo basket full of materials.

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

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

Although Li Weidong didn't know their names, he knew that they were all radio amateurs.

Making an ore machine is a very small and very compelling hobby, which is similar to playing a racing car and participating in the Haitian feast in later generations.

Likewise, there is a need for communication between fans.

The side room of the chemical materials sales department has several tables and tea, which is the best place to communicate.

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

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

"I heard my buddy from the Ordnance Institute said that the Q value of the 222 air variable capacitors produced by military aircraft can reach 15000. If you build one, you will definitely be able to receive two more radios."

"That is, the materials in the chemical materials sales department are all from Datong, so it is better to go to the laboratory of the Ordnance Institute."

The one who said this was a young man in uniform.

Li Weidong also knew him, but did not know his name.

All I know is that everyone calls him Lao Bai.

Wearing a general all day long, wearing a small military cap, and coaxing cowhide.

If in the past, Li Weidong heard this and smiled lightly.

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

Not today.

"Old white, the performance of air variable capacitors is not necessarily better than the performance of small sealed variable capacitors."

These unreasonable words echoed in everyone's ears like a thunderbolt.

They turned their heads in unison, and saw a young man with a bamboo basket standing there quietly. Although the young man was wearing a tattered cotton jacket, he had a heroic spirit that could not be concealed.

Hu Guangliang was the first to react.

He stood up, with a smile on his face, came over, and punched Li Weidong: "Weidong, you are wearing a ragged cotton jacket today, I didn't recognize it just now.

Where did you go these days, I haven't seen you after coming here several times, I thought you weren't working in the sales department anymore. "

They are all young people who like to be lively.

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

Over time, he is half a radio amateur.

Although there is no actual hands, the theoretical knowledge is weak, but the familiarity with various materials far exceeds these enthusiasts.

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

"It's true that I quit. I don't want to think about my brothers." Li Weidong grinned.

The two chatted for a while, but the general next to him was not happy.

"Weidong, everyone who plays with mining machines knows that the quality and performance of different variable capacitors are different. A small sealed variable capacitor has worse performance than an air variable capacitor, which is due to their production. principle."

Hu Guangliang also said: "It's not that my buddies don't give you face today, it's that what you said has violated scientific principles. If in the past, I would have made do with these materials. If it doesn't work today, I'll return it."

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

The proposal was immediately embraced by the crowd.

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

"Wei Dong is an honest man. Although his education level is not high, he knows more about mining machines than I do."

"That is, which one has the highest Q value, you won't know if you test it."

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

He also wanted to know what the Q-values ​​of small sealed variable capacitors could achieve.

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

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

"Sister Niu, it's like this"

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

"I don't understand what you're talking about. What tools do you need for testing? My sister will give you an order. Don't let these guys 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 can they not return the goods, but they have to buy them again." Li Weidong took the order and went into the warehouse.

Five minutes later, he came out with a fist-sized copper coil, a frequency measuring instrument and several patent leather copper wires in his hand.

Hu Guangliang has put the variable capacitor on the table.

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

"Do you have any objection to this method?"

Hu Guangliang nodded: "No!"

Lao Bai nodded: "No!"

Everyone nodded: "No!"

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

At the moment of connection, the dark blue screen of the frequency meter lit up.

The line of numbers that appeared above made everyone gasp.

"23000!"

"My God, look, there are 23000, which is much higher than the air company of military aircraft."

"Impossible, absolutely impossible, this is unscientific!" Lao Bai raised his head suddenly and looked at Li Weidong with an incredible look on his face.

"Did you do something wrong?"

Is this not worth losing?

Li Weidong frowned and was about to speak when Hu Guangliang stopped him.

"Old Bai, you don't know who Weidong is. How can you be a fool? Besides, what does it have to do with Weidong if you sell this variable capacitor today?"

Old Bai was speechless.

But he is a master who will not give up until the Yellow River.

I picked up the frequency tester to test it again, and looked at the dazzling 23000 above, and then I had to accept this result.

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

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

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

In principle, the performance of air variable capacitors is better than that of sealed variable capacitors.

but.

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

Air capacitors are new products, and the technology is generally not as mature as the old products. "

After speaking, Li Weidong looked around the crowd: "So, this is very scientific."

(End of this chapter)