Analog circuits, that is, diodes, transistors, etc., the internal signal is continuously changing, and the function is achieved by amplification, filtering, etc.

The digital circuit, which is mainly the gate circuit and the switch circuit, is combined through various logical relationships to realize the change of these digital signals.

With the development of electronic technology, the transition to digital circuits is inevitable, through the operation of each digital signal, to achieve specific functions, such as the most urgently needed pulse Doppler radar in China, it must be processed by digital circuits, and the operation of Fourier transform to eliminate clutter on the ground.

However, almost all of the old comrades in China came from analog circuits, even Tu Lao, who had only had preliminary contact with the principles and operation of specific digital circuits in the past, and only after they began to negotiate with Marconi Company did they vigorously supplement their knowledge in this area.

Therefore, the concern just now is reasonable, and I am worried that the domestic introduction of avionics equipment will not be thorough and cause mistakes in changing the aircraft, so I consider contracting Marconi to be responsible.

Of course, Marconi agrees with such conditions, although Marconi itself is only an equipment manufacturer, but they can go to the British aircraft company to cooperate, and they can also make more money in this way, how can the other party help for no reason?

At present, this introduction project is a key project of the Air Force and the Third and Fourth Aircraft Departments, and it makes sense for everyone to hand over to foreign countries for fear of delaying the progress.

However, Tu Lao did not agree with such a point of view, and Qin Feng did not agree with it either.

Hearing this, Tu Lao wanted to express his opinion, and when he looked at Qin Feng's puffed face, he said, "Comrade Qin Feng, what do you think?" Tell me about it. ”

"Tu Lao, I think, we can do this matter ourselves, after all, the plane is our own, we spent so much effort on the J-7, and we also modified the new J-7, we have already eaten the plane thoroughly, where can we take it out and ask someone to modify it, don't you feel blushing?"

As soon as Qin Feng said this, all of a sudden, the comrade who had just said that he wanted to invite a foreign country to change his face turned red.

"Moreover, if we ask someone to change it, I don't think they will help us for free, and they should ask for our consulting fees, right? Our country is still very poor, let's do it ourselves, so we can save the country precious foreign exchange. ”

Everyone knows how poor the country is, and the foreign exchange reserves are pitiful, and they must not spend money lavishly.

"Comrade Qin Feng, we all understand these truths you said, but we are not familiar with these avionics, and it is risky to change them ourselves." The red-faced comrade said.

"That's right, if we change it ourselves, although there is a risk, we can force ourselves to learn more things in technology, and we will have to come out sooner or later if we are familiar with the road of advanced avionics. At the beginning, we were blocked by foreign countries, so we could only do our own thing, but now it is easy to have a window to the outside world, do we still want to continue to stop? Now is a great opportunity to learn! ”

"Yes, yes!" Tu Lao spoke: "Comrade Qin Feng is right, this road, we will have to go sooner or later, now, even if we don't sleep, we have to flow out of this road!" ”

Tu Lao was the person in charge of the entire project, and as soon as he made such a statement, those comrades who opposed it had no opinion.

This road must be taken, and now this opportunity must be seized!

When everyone finished talking, it was already two or three o'clock in the middle of the night, and Qin Feng remembered the trip in Egypt again, and it was the same!

After a few hours of sleep, everyone rushed back to the meeting for the new day.

Peterman was a tall and burly Englishman, with a pair of sharp eyes on top of his hooked nose, as if he could see everything, and next to him was a short man, and this short man's eyes, purring, looked like a smart fellow.

At this point, everyone is seated, and the new day of meetings begins.

"There are a couple of minor issues with these projects that we discussed yesterday." Tu Lao said: "The performance indicators of this radar rangefinder are not very clear, its maximum detection range, is it with a radome or without a radome?" ”

After Tu Lao finished speaking, Qin Feng started translating on the side, and when he found that the other party had changed to a translator, the Englishman on the opposite side was still a little curious, where did this young man come from?

Moreover, this young man not only pronounces clearly, but also uses the words of these professional terms quite accurately, in these technical documents of his own, he deliberately ignores the radome and does not appear this word, and the young man on the opposite side uses the words quite accurately.

It's hard to say, after all, they don't know what the performance of the J-7's radome is.

"This, I shouldn't need it, right?" Malina said.

This Englishman, as expected, wants to be ambiguous! Qin Feng secretly thought in his heart, of course this is not possible! How can you fool them around?

"This is a necessary indicator, our own 226 radar rangefinder, the detection range has reached 15 kilometers, your air patrol radar, this maximum detection range of 19.5 kilometers, should be through the radome, right? Otherwise, it would be no different from ours. Qin Feng continued.

This time, before Tu Lao could speak, Qin Feng said it directly.

The British on the opposite side were stunned for a moment, that's right, their Western technology is advanced, and in their eyes, all the equipment in China is backward, how can it be inferior to theirs?

"That's right, of course, with a radome, and if it weren't for it, we would have a detection range of more than 20 kilometers long ago." Malina said on the other side.

He didn't lie, this air patrol radar rangefinder is a mature radar of theirs, and with a slight increase in power, it can exceed 20 kilometers.

So, on the terms of the contract, the indicator of the radome was added, and the Britons present did not expect that when they were installed and tested two or three years later, the distance through the radome would not meet the standard, and when they wanted to repay the debt, they had been deducted by the terms of the contract.

When introducing projects from abroad, it is necessary to take them seriously, thoroughly study every clause in them, and sign the documents in a daze, and you will suffer a big loss in the future.

In the introduction of Spey, it has suffered a big loss, and it was supposed to introduce all the technologies together, but what is the result? When it came time for the specific production, the British began to play tricks, insisting that third-party patents were involved, such as the production of compressor blades, and money must be added!

As a result, the technology that should have been mastered a long time ago was only studied by itself after several decades, and this contract, if not carefully studied thoroughly, would definitely go wrong.