In the open space of the camp, there stood a makeshift shelf made of wood. Pen ~ fun ~ pavilion www.biquge.info

The sun fell and looked up at Ga Li Guang on the shelf with an anxious face, and shouted, "Ga Li, you climb higher again!" ”

Ga Li Guang held the walkie-talkie in one hand, agreed, quickly climbed to the top of a wooden pole, put the walkie-talkie to his mouth and shouted,

"Anyone?"

……

"Anyone?"

……

Testing the communication distance of the walkie-talkie in the electromagnetic environment of the Ming Dynasty was also one of Sun Yi's tasks this time.

The two walkie-talkies that Sun Yi bought on the Internet are claimed to have a maximum call distance of 15 kilometers and a transmission power of 12 watts, which are a well-known brand. However, none of these three Sun believed it.

The frequency band of domestic civilian walkie-talkies is the U-segment with a wavelength of 70 cm, which has limited diffraction ability of electromagnetic waves and propagates completely along a straight line. Since the earth is a curved surface, the maximum distance between two walkie-talkies at a height of 1.7 meters above the ground is theoretically 15 kilometers.

As for the twelve-watt high transmitting power claimed by the seller, Sun Yi didn't take it to heart at all. The maximum power of a walkie-talkie for civilian use stipulated by the State Radio Regulatory Commission is half a watt, and the transmission power of Sun Yi's own shortwave radio station is only five watts when connected to an external power supply.

In addition to listening to radio waves from 160 meters to 30 centimeters, Sun Yi's shortwave radio station can also transmit in the form of amplitude modulation, frequency modulation, single sideband, and sine wave on amateur radio channels ranging from 160 meters to 10 meters, as well as amateur radio channels of 6 meters, 2 meters, and 70 centimeters. Dual-way listening, 30-minute waterproof level, built-in barometer, thermometer. It can be connected to an external power supply, can use batteries, and can also be powered by eight No. 5 batteries in case of emergency.

More than once, Sun Yi took this step to the desert island to establish a remote radio station, which "ham" called DX.

This small and powerful radio station has a small drawback: it cannot talk to regular civilian walkie-talkies in China. The 20 civilian walkie-talkie channels promulgated by the National Commission are not within the scope of this radio station's transmission permit, which means that this radio station can only listen to and cannot speak when it encounters regular walkie-talkies.

So Sun Yihao bought two ordinary walkie-talkies, and only required them to be strong, simple, lithium battery, and USB chargeable.

As an old "ham", Sun Yi believes that "good equipment is not as good as good antennas." ”

For a 70 cm wavelength walkie-talkie, the best antenna is the one that is set up high. Sun Yi once used a walkie-talkie on the top of a snow-capped mountain in Qinghai to pass with a donkey friend dozens of kilometers away. So before leaving, Sun Yi deliberately built a high platform in the camp. Theoretically, for every one meter seven of the heights, eight kilometers of straight-line travel can be added.

Before leaving, Sun Yi's shortwave radio station was also modified.

In fact, whether it is a radio or walkie-talkie, the manufacturer's hardware equipment supports full-band transmission. However, in order to meet the requirements of local radio regulatory agencies, manufacturers will use jumpers or software to lock the frequency bands that are not allowed to be transmitted by local regulations.

As long as a few resistors were simply soldered off, Sun Yi's radio station became a full-range transmitting station from 160 meters to 10 meters, 7.5 meters to 1.3 meters, and 1 meter to 0.5 meters, covering part of the medium-wave broadcasting, full-range shortwave, FM broadcasting, and over-the-air television broadcasting in later generations.

This is actually a "secret" that every old "ham" in later generations knows, and it is also something that every real "ham" in later generations despises to do.

The "hams" called the unlicensed field stations "sausages". The biggest difference between "ham" and "sausage" is the protection of the channel. A crowded channel is like a noisy room, and no one can hear it clearly. The "ham" approach is to shut up immediately and quiet the room, while the "sausage" approach is to immediately increase the volume and let its power "cover" others.

In addition to radio and television signals, these radio frequencies also include life-and-death maritime, air traffic control, rescue, commercial and communications frequencies. The joy of "ham" is to constantly connect with new people, not to interfere with normal communication.

But in the fifth year of Chongzhen, the only wireless devices in the world were Sun Yi's three radio stations and a mobile phone. Sun Yi can play as much as he wants.

Sun Yi adjusted the frequencies of the three radio stations to the same.

The channels of the two walkie-talkies are simply locked, except for the power on volume knob and the call transmitter button, the other keys are all open to remove the conductive rubber. The walkie-talkie then turned into an extremely point-and-shoot machine.

The antenna of the shortwave radio station was changed to a special 70 cm wave length to match the frequency of the walkie-talkie, and the rest of the antenna accessories were left in the camp.

On a shortwave station, set an FM radio channel.

Transmitting on this FM channel, the FM radio in Sun Yi's mobile phone can be accepted, so the mobile phone has become a semi-wireless device.

Sun Yi turned on the radio in the side pocket of his backpack, and Ga Li Guang's call immediately came from the radio, "Does anyone have any?" Is the master here? Have you all eaten? ”

Sun Yi said to the external Mick Feng fixed on his left chest: "This is the exploration team. Fifty-five. I'm Sun Yi. Call quality fifty-nine. Come to an end. ”

Ga Li Guang's happy voice came, "It's through!" It's done! Fifty-five, fifty-five, I'm fifty-nine here. Come to an end. ”

"Ga Li Guang, remember to report your name in the future. Second contact a quarter of an hour later. Seventy-three. Come to an end. ”

"Oh. You are also seventy-three. Come to an end. ”

Sun Yi instructed the four orphans, "Install the radio!" ”

The four orphans quickly took out some special small iron cans, measured the blue alum, poured them into the iron cans, added water to the scales in the cans, and "snapped" the wooden lids. Take out the plaster gauze, quickly dip it in water and wrap it around the small iron jar and the wooden lid, leaving only two terminals, one iron and one copper.

This is a "military battery" that Sun Yi himself is reluctant to use.

Each battery voltage is 0.7 volts, only need to carry iron cans and blue alum, and now use and assemble. Solidify with plaster to prevent water and impact.

The orphan boss put a curtain made of a baby on his chest, and the fourth child helped him tie it behind him. There are two rows of cloth pockets on the curtain, three in each row, and the four old people quickly stuff the iron can batteries into the cloth bags one by one.

The two connected the batteries in series, and the last two wires were connected to the walkie-talkie-talkie's original lithium battery Sun Yi had already put it away.

The boss stuffed the walkie-talkie into a single pocket on his left chest, and said loudly to Sun Yi, "Brother Yi, the radio installation is complete!" ”

Sun Yi looked at the time, eight minutes, and said, "Yes, call the camp now!" ”

The boss held down the launch button of the walkie-talkie with one hand, lowered his head and shouted at the machine: "Camp, camp, here is the second station of the exploration team to call, here is the second station of the exploration team to call, please answer when you hear it!" Come to an end. ”

Immediately a reply came over the intercom, apparently the camp had been listening. "Exploration Team 2, this is the camp. Fifty-five. I'm Ga Li Guang. Call quality fifty-nine. I'm on the ground now, and the Lordship of the Fallen Sky wants to talk to you. ”

Kara made a noise, and the walkie-talkie sounded: "Well, who is that, have you eaten?" ”

A moment of silence.

The boss replied, "Fifty-five." This is the second station of the exploration team. After speaking, you have to shout the end. It's best to learn politeness before getting on board. Come to an end! ”

The voice of the sunset rose an octave, "Which one are you?" Dare to talk back to me! ”

A moment of silence.

The boss said calmly, "You don't even know who I am? ”

The sun is falling, "Report your name!" ”

The boss said into the walkie-talkie: "The quality of this call is fifty-nine." Everything works fine. The next call will be an hour later. Ninety-nine. Come to an end. ”

The sun fell and yelled: "Speaking human words, it's still ninety-nine, I think you are eighty-eight!" ”

The boss calmly turned off the walkie-talkie.

(Author's note, Ham Dialect, Fifty-Five: Handshake.) Seventy-three: This is a salute. Ninety-Nine: Get out. Eighty-eight: Kiss the baby)