From the Badaohe area of Liuqiu Island to the Wenlai estuary area of the Boni Country area, it takes about 20 days to make a navigable trip...... This is really not a long time for this plane, and everyone is used to it. Pen, fun, and www.biquge.info

However, Wang Defa's family and Zhang Guoan's owner both felt that it had been too long, and it took two months for a letter to go back and forth!

There is also an area in the middle of the two places, that is, the area called the three islands on the nautical chart of the Great Song Dynasty has not yet been used.

It's actually the Philippines of the world...... Of course, now that place is still similar to the Boni Country region, there are several large and small tribes, and the largest tribe calls itself the Ma Yi Country.

Mayi is a Turkish language, which means the land of black people.

The country of Mayi is much smaller than the country of Boni, and is nothing more than a settlement of more than 1,000 households, ruled by a chief, in the form of a social organization of village and community alliances.

It is also the center of trade and commodity distribution in the northern part of the three islands, and it has close trade with the nearby islands.

The chief has the power to control trade, as well as military and judicial powers, but he consults with the elders...... At this time, they had not yet entered the stage of feudal dictatorship, and they were still in the form of primitive tribal management.

They are located in gentle mountains, fertile land and a warm climate.

They would boil salt, make wine, weave linen and other simple manual techniques.

Ma Yiguo once carried goods to Guangzhou for trade in 982, that is, the seventh year of the Taiping rejuvenation of the Great Song Dynasty.

They exchanged their native yellow wax, tortoiseshell, pearls, betel nuts, etc., for porcelain and iron ware of the Great Song Dynasty, as well as silk that they liked very much.

Maritime merchants have been here for a long time, but often after trading a few shipments of goods, they don't have to go there for a year, because their numbers are too small to have much room for development.

Of course, Wang Defa's family knew that the Ma Yi Country area was located at the northern tip of Luzon Island among the three islands, and there were also a large number of gold, copper, iron minerals, and many tropical hardwoods...... But it's sparsely populated and rainforested, making it too difficult to mine.

The population is less than a certain level, and even how to get to the mining area is a big problem.

It's better to develop hardwood mining there first...... Of course, the most laborious and cheapest way to get the natives to be willing to cut down for the island is to do it commercially.

However, another important role of Ma Yiguo has emerged, and it can be regarded as a future radio contact center.

In this way, whether it is from the Badaohe area of Liuqiu Island or the Guangzhou area of the Great Song Dynasty, it can be transmitted through the radio receiving antenna in the Mayiguo area...... Judging from the current technical capabilities, it is still possible to easily transfer the signal to the mouth of the Wenlai River.

The technology of the spark radio transmitter is simple, and the radio waves it emits are electromagnetic waves, which are similar to the ripples of a pond...... But the energy of that radio wave gradually weakens during propagation.

Therefore, as long as the power of transmitting radio waves is sufficient, the spark radio transmitter can emit any long-wave, short-wave, high-band, and low-frequency radio waves...... Just send it according to all channels, all channels can be used!

If someone tries to use the electronics of that world next to it at this time, then they will find that they have encountered the blockage of the omnichannel jammer!

This is just a casual example.

Of course, if you want to transmit a long distance, its transmitting power must be large, not to mention this, the key is that the transmitting antenna it needs must also be huge.

If the transmission distance reaches about 1,000 kilometers, then its transmitting antenna is at least 15 meters high!

It is also necessary to choose a suitable terrain location in advance to erect it...... The antenna is too tall and too big, which makes it easy for others to be curious.

The result of human curiosity is often the destruction of the thing that arouses their curiosity.

Therefore, the transmitting antenna should be lower...... In addition, the power is too great, and the requirements for the power supply are too high.

About 500 kilometers only need an antenna about 10 meters high, which is still within an acceptable range, and with a little camouflage, you can hide it from others.

The principle of the spark transmitter is simple, as long as you master a core content, you can understand.

That's breakdown, and it keeps breaking.

When the high-voltage power supply it needs is continuously charged for a capacitor, the voltage at both ends of the capacitor will of course continue to rise, and when it reaches a certain voltage to break through the gap between the sparks, the voltage of tens of thousands of V is converted into a current pulse, and the arc reaches the circuit on the other side.

This circuit is called the LC oscillation circuit.

When a pulse of current rushes into the Lc oscillation loop, it continuously generates an arc pulse between the capacitor and the coil inductance...... The higher the power, the longer the spark length of the arc, and the louder the "hiss" and "hiss" sound it emits!

At this time, if the energy of this oscillation is radiated through the antenna, a radio signal will naturally be formed.

Of course, its frequency band is not adjustable...... There is no need to tune in, they are the only ones who can send radio signals in this time and space, and they don't have to worry about confusion or interference.

And the radio use environment in this time and space is super good...... But there is also the constraint of distance.

Therefore, it is necessary to erect another transfer station between Liuqiu Island and the Wenlai estuary area.

In the final analysis, it uses spark discharge to produce full-frequency electromagnetic oscillations, and as a result, its oscillation frequency is determined by the inductance and capacitance of the coil inductance and capacitor.

As for the coil inductance and capacitor, the structure is extremely simple, and for them, with a little care, they can completely guide the craftsmen of the Great Song Dynasty to make it......

The structure of its receiver is simpler, and it can be used in a structure similar to that of an ore radio.

Of course, there are also certain requirements for its receiving antenna, which is basically the same as the transmitting antenna.

In fact, it is the training of the operators that is more laborious...... It can only be cultivated little by little, and there is no rush at all.

Wang Defa's family knows that Zhang Guoan's owner must be processing relevant equipment carefully, but he is not in a hurry to use it now.

He wrote another letter to his friend, mentioning another of his views, about the Great Song Dynasty.

If we had beaten away the Tatar bandits, would they have maintained their current attitude?

If so, for how long?

If you can't keep it, what will it become?

I dare not say whether this nation will bully the weak and fear the hard, and the practice of embracing pragmatism alone adds a lot of uncertainty.

When this letter arrived on Liuqiu Island, Zhang Guoan, the owner of the island, also had to think about it seriously.

There will definitely be changes in the Great Song Dynasty government, and it is difficult to say what kind of changes, but it can be deduced.

He believed that his friend must have thought about it, but he just wanted himself to deduce it too, and then everyone would discuss it.

Wang Defa's family couldn't come back for a while, because the plan to develop Belitung Island in that world had already been put on the agenda.

Belitung Island is called Tin Island in that plane.

Its location on that plane is between the South China Sea and the Java Sea, covering an area of 4,850 square kilometers.

The entire island is roughly square in the form of a ruin hill lowland, with the highest point being 510 meters.

The islands are flat or slightly undulating with a few hills, and the central part is a treeless plain covered with thatch.

With proper development and a few more wells, pepper and rubber can be grown on this island, and sea cucumbers are abundant along its coast.

The people of the Great Song Dynasty are not popular to eat it at this time, but it can be cultivated slowly. (To be continued.) )