A nation's industrial development begins with junior engineers.

fVCO = fREF x N/M, where fVCO is the frequency of the voltage-controlled oscillator (VCO), fREF is the reference frequency, and N and M are the division ratios of the frequency divider.

Then, f_capture = f_REF / 2 x (1/f_charge + 1/f_discharge). After capture, it's time to lock...

Finally, add the loop bandwidth BW = fVCO/Q loop.

Okay, that's all.

As for what these formulas are, even Xiao Dai Mao himself didn't know after writing them down.

It wasn't until Jiang Xia copied the last line of words in his mind onto paper and saw that familiar word—PLL—that he suddenly realized what was going on.

Isn't this a basic formula used in phase-locked loop (PLL) circuit design?

Hey, what I wished for has come true! With this electronic circuit, the problem of laser rangefinders is largely solved. Although later phase-locked loop circuits are all digital, it's not impossible to build one using modern electronic modules, just with a lower level of integration.

At worst, we can partition the code and create a dedicated version!

It's important to know that this device can not only generate stable high-frequency electrical signals to provide driving signals for the laser emission module, enabling it to emit a series of stable laser pulses at precise time intervals, but it can also generate laser pulses with different frequencies and duty cycles according to different ranging application scenarios.

Most importantly, it can provide a time reference. To achieve meter-level measurement accuracy, a laser rangefinder would need at least a 150MHz operating circuit.

Hmm? You mean Jiang Xia tricked Comrade Pu Fang into developing a quartz crystal oscillator?

That's because we couldn't get it working!

Moreover, quartz oscillators have a fatal flaw: their frequency!

Although quartz crystal oscillators have very high frequency stability and accuracy, their frequency is fixed once it is manufactured. Want to change it? That's impossible.

PLLs are different; they can not only achieve phase synchronization, but their frequency is also adjustable. These two points alone make PLL oscillators far superior to quartz oscillators in terms of applicability.

Moreover, this thing can be used not only in laser rangefinders, but also in wireless communication!

In particular, the initial version of the modem used an LC oscillator. Although the frequency stability was relatively good, the current power environment in China meant that this type of circuit, composed of "inductors" and "capacitors", was generally at risk of exploding at any time.

Yes, it explodes in a physical sense, and the sound is quite crisp, crackling and popping, comparable to the firecrackers that everyone loves during the Chinese New Year.

However, Jiang Xia had another question when it came to firecrackers.

First, I tidied up what I had written, then I ran to the stove that Battalion Commander Liu had set up:

"Battalion Commander Liu, why don't you use firecrackers to scare away birds? These clumsy little chubby birds, one firecracker should be enough to scatter most of them, right?"

"five minutes!"

Liu Xiangyang, who was roasting birds for Jiangxia, looked up with a frustrated expression: "You said it yourself, this bird is stupid. We've set off firecrackers before, but they only lasted so long. Once things calmed down, it flew back again."

"After a while, this silly bird seems to have gotten used to it, and it doesn't work anymore when we play it again!"

Without any hesitation, Old Wang grabbed two roasted silly birds and stuffed them into his mouth.

"Why don't you clear away the grass on both sides of the track? Problems need to be addressed at their root!"

"Pah! Cut off the roots? These grasses are natural camouflage, aren't they? This is a combat airfield for Battalion Commander Liu; it's all about concealment! I spotted it from the air..."

Jiang Xia happily accepted the roasted bird from Battalion Commander Liu and devoured it one after another.

Mmm, they really are bite-sized. These little chubby birds are even smaller than sparrows, but they're packed with juice when roasted. They're truly a delicacy!

"Yes! Concealment is one aspect, but also, our airport is surrounded by waterways. Without this grass, there's a risk of soil erosion, and a collapse would be even more troublesome!"

While dodging Old Wang's claws, Battalion Commander Liu continued to feed Jiang Xia, explaining as he went.

"However, your gyroplanes are different. Look, those silly birds have flown away and haven't come back yet! It's been more than half an hour! Enough time for a plane to take off and land."

"So..." Battalion Commander Liu forced a smile, "Could Xiao Jiang make two more for us? I'll submit a report to the higher-ups right away!"

Jiang Xia scratched his head: "Okay, but, Battalion Commander Liu, could I fly a few more rounds then?"

"No problem at all! You're supporting our work by not only providing equipment but also helping us scare away birds. Hehehe, this is a model of military-civilian cooperation!"

Upon hearing this, Battalion Commander Liu was stunned. "Good heavens, how could I say something so shameless..."

Well, since I've already said it, let's just put it into practice.

"Jiang, wait here, I'll go write a letter of commendation right away..."

After watching Battalion Commander Liu leave, Jiang Xia took over the task of cooking "Little Fatty Bird". There was really nothing complicated to do; he simply roasted it until it was golden brown and then sprinkled it with a little salt.

Barbecue seasoning, scallions, ginger, and garlic? No, absolutely none.

Even so, this silly bird still smells incredibly delicious when roasted.

"Uncle Yang, why aren't you eating?"

Yang Youning pulled out a small cage containing several live animals. The tiny creatures huddled together like little cotton balls, and with their tiny black bean-sized eyes, they were actually quite adorable.

"Let's get a few for the kids to play with..."

"Uh, I thought you were going to say that it looks cute but you can't bring yourself to eat it."

"No matter how cute you are, is it more important than filling your stomach?" Yang Youning rolled his eyes at Jiang Xia, annoyed.

Then, he snatched the skewer from Jiang Xia's hand and devoured the silly bird on it in just a few bites. But looking at the adorable creature in the cage, Jiang Xia's movements slowed down.

The bird looks so familiar... Didn't that "Tibetan fox face" TV show in later generations make a special feature about it?

As he thought about it, the name "Northern Long-tailed Tit" entered Jiangxia's mind...

Oh my god, how did I eat it?

This creature almost became the national bird of China.

Jiang Xia was a little flustered at this moment, but looking at the plump, oily, tender meat, he couldn't help but stuff it into his mouth.

Ha, we've eaten everything that could be punished, what's the difference between you and someone who's not even on the list of protected animals?

Really fragrant!

"We have a holiday the day after tomorrow, and the factory's welfare benefits prepared today should have been mostly claimed by the employees. But it seems that our sister companies sent a lot of things this year. Each employee received some, but there's still a small amount left over. I'm thinking of sending a batch to the comrades who have helped our factory in the past. What do you think?"

"Hey, Uncle Yang, you've finally figured it out? You're even learning how to do favors now? By the way, what kind of holiday are you taking?"

"What holiday? It's Chinese New Year! Silly boy." Yang Youning gave Jiang Xia a disdainful look: "It's only in New China that you'd be starving to death! Back in the old days!"

"Nonsense! I can grill meat and make stew! As for delivering things, you figure it out yourself, why are you asking me for advice?"

"Tsk, I was a bit stunned, but I can tell who those units are doing it for. When you get back, make a list yourself and deliver it door-to-door. For some units that are far away, I'll have the transport team make a trip. Here's the list of those units, see if it's suitable..."

Jiang Xia took the list and looked at it. Hey, the quantity wasn't much, but the variety was great.

Rice, meat, fish, and cloth—basically everything was provided.

The rice was delivered by Director Zhao of Zhuzhou 331 Factory, the meat was delivered by the Ministry of Railways, the cloth was probably a product from Jinan, and the fish, needless to say, was delivered by a bigwig from the Navy.

Looking at the quantities on the list again, I exclaimed, "Hey, Uncle Yang, this isn't your work, is it? When did you become so meticulous?"

"That old idiot, he's a real genius in this area!"

No wonder, you couldn't have come up with such a thoughtful gift plan.

I wonder how the support and construction on Li Huaide's side is going. I haven't seen him in a long time, and I miss him terribly!

However, even "Teacher Zhu's" students who came to support the research are on this list, so why are there no relevant leaders from the Ministry of Machinery Industry?

Is there any deeper meaning behind this?

Or, should we go back and give them a call?