-
1. Long-wave radio stations are still in use, and long-wave mainly relies on ground wave propagation.
2. It's possible. A radio with long-wave capability (e.g. Tecsun PL660 or Tecsun PL365, etc.) is required
3. The medium wave is between 500-1600kHz, which is propagated by sky wave and ground wave, mainly ground wave propagation during the day, and sky wave and ground wave propagation at night. As a result, more medium-wave radio is heard at night than during the day.
Shortwave 1600kHz-30MHz, mainly propagated by skywaves, because the signal can be reflected back and forth between the atmospheric ionosphere and the ground, so the propagation distance is long.
Long waves range from 100 kHz to 400 kHz and are propagated mainly by ground waves.
4. It is possible to listen to it, provided that the military signal is an analog signal, but now the military uses encrypted digital signals to transmit due to its special conditions, and ordinary people cannot listen to it without a special decoder.
-
First. In use, the long wavelength is used to exceed the water depth and will not be absorbed by the water.
Second, it is possible if your antenna is ten meters long and wide.
Third. Bands.
Fourth. It's possible, but the military ones are encrypted, and you can't listen to them even if you receive them.
-
Long wave can only be used for communication with submarines, and at present it is still the only effective and reliable air-to-submarine and shore-to-submarine communication methods, which can ensure that submarines can receive individual commands underwater.
-
1. Long-wave radio equipment maintenance is expensive, transmitter power consumption is large, and the popularity of the Internet and regional FM radio has led to a decrease in listeners, European long-wave radio is generally in a stage of decline, the daily broadcast time is reduced, and several large transmitter stations are shut down in various countries every year. Recently produced radios have rarely included the beam cons LW (long wave) band.
2. The minimum amateur frequency stipulated by the state is about 160 meters, and long wave (LF) refers to electromagnetic waves with a wavelength range of 10 1 kilometers (the frequency of the rubber group is 30 300 kHz).
-
Shortwave radio stations from 1700kHz to 30MHz, mainly used for long-distance radio communication, because shortwave propagation by sky waves, the signal is reflected back and forth between the ionosphere and the ground, a 100W shortwave radio can be transmitted all over the world under good conditions. Therefore, shortwave stations are often used for international broadcasting, maritime communications, timing services, amateur radio communications, etc.
Long wavelengths are long, with frequencies between 100kHz and 300kHz. It mainly relies on ground wave propagation, and is mainly used for timing services and long-wave broadcasting (which is rarely used now).
-
There are two ways to represent radio waves: wavelength and frequency, China is used to using frequency to express, while foreign countries use wavelength.
The longer the wavelength, the lower the frequency.
The long-wave conduction distance is long, and it is generally used in shipping and other occasions; The short wave distance is also far but shorter than the long wave, and is used for broadcasting, communication, etc.
Of course, there is, because as the functions of the Mini Program become more and more powerful, the benefits it can bring to enterprises and merchants are also increasing. The following will briefly introduce you to a few, the benefits of mini programs for enterprises and merchants: >>>More
To face the computer for a long time, it is best to learn to type with five strokes, which is also a general trend of playing with computers, it may feel a little difficult at the beginning of learning, in fact, you can get started, I am self-taught, and I will learn it all in a week. >>>More
Rabies is an infectious disease with an incubation period that can be very long, generally the onset of the head and face will be earlier, the onset of the limbs will be later, and some people will not develop the disease until more than ten years after being bitten by a dog. It is generally believed that the sooner the vaccine is given, the better, but as long as there is no disease, the vaccine will work, and if the injured animal has symptoms, then rabies immune globulin should be injected. The second is whether the wound was properly treated at that time, whether it was thoroughly rinsed, and if the wound was not very large, it should not be sutured. >>>More
Peach gum can really make your own ** better, although I feel that the taste of peach gum is not very different from white fungus, but since the nutritional value is hundreds of times, then you should drink more peach gum. <>
Of course, the essence of the management will be to get rid of the problem of simple bookkeeping by junior accountants, and increase the overall view and overall view based on numbers to improve the money utilization rate of the enterprise, which can provide better development for the development of the enterprise and enhance the value of simple bookkeeping. Study hard, and the future will be promising.