The signals sent by radio waves are written on a piece of paper in a certain format after being received by the receiving station. This piece of paper for recording information is called a telegram. Of course, the sender should also write the information on paper first. This kind of paper is also called telegram. Send and receive telegrams immediately. Radio is a communication tool used to send and receive telegrams. Telegraph is just a special stylistic format. It's a bit like the relationship between mobile phones and text messages.
How does the radio station get the enemy's telegram? Use an antenna to receive electromagnetic waves, and then decode them according to the information hidden in the code, so as to get the information you need.
How far can the high-power telegraph office go? Medium and long waves cannot pass through the atmosphere.
The radio station sent a telegram with punctuation ellipsis.
Morse code is a telegram? Morse code.
Different translations are sometimes called Moore Code. * stands for Didi,-stands for Da, as shown in the table below. For example, Didi represents the letter U and Didi represents the number 5. In addition, please don't be trapped in the form of Didi. When we actually generate the password, it may be converted into many forms, such as 0 and 1, which will confuse you into binary, and so on. Morse is a very common form of password in our life. For example, this is used for telegrams. Next time you watch a war movie, there is a telegram in it. You might as well try to decipher the contents of the telegram yourself and see if the director makes up a random password to deceive the audience. Because this password is also relatively simple, there is no fuss.
A *- B -*** C -*-* D -** E * F **-* G - *
H **** I ** J * - K -*- L *-** M - N -*
O - P * - * Q - *- R *-* S *** T -
U **- V ***- W * - X -**- Y -* - Z - **
figure
0 - 1 * - 2 ** - 3 *** - 4 ****-
5 ***** 6 -**** 7 - *** 8 - ** 9 - *
Common punctuation marks
Period *-*-*-comma-* *-question mark * *-* *
Dash-* *-hyphen-* *-score-* *-*
A telegram or a telegram? A telegram?
Is radio station a general term for radio 1 and radio stations? Radio station refers to AN/PRC- 152 radio station used in radio communication service or radio astronomy industry.
One or more transmitters or receivers required by the service, or a combination thereof (including accessories). 2. refers to the radio station. Include AM broadcasting and FM broadcasting. Broadcasting can be divided into wireless broadcasting, wired broadcasting and data broadcasting. [transciever's technical equipment for radio communication. It consists of transmitter, receiver, antenna, power supply and accessories. 4. Internet radio, a radio station built on the network. Internet radio moved the traditional radio station to the Internet. There are no bulky cataloging equipment here, only portable computers. There is no launch tower, only a network extending in all directions; You don't need a radio to listen to the radio. You just need to sit in front of the computer and click to hear the voice of the host. Network radio station refers to converting the audio or video data being played in the computer into a format that can be directly transmitted on the Internet through an encoder. Users can download the encoded audio information when logging in to the radio station website, and then convert the audio information into sound through related software such as Realplay or Winamp. Network radio stations do not need to occupy satellite frequency bands and frequency resources, and the broadcast effect is affected by network bandwidth. Network radio station refers to converting the audio or video data being played in the computer into a format that can be directly transmitted on the Internet through an encoder. Users can download the encoded audio information when logging in to the radio station website, and then convert the audio information into sound through related software such as Realplay or Winamp. Network radio stations do not need to occupy satellite frequency bands and frequency resources, and the broadcast effect is affected by network bandwidth.
Radio is a machine composed of mechanical devices, electronic devices and magnets. It uses electric energy to convert radio signals and can listen to audio signals sent by radio stations. Also known as radio, broadcasting, etc.
It converts the high-frequency signal received by the antenna into audio signal after detection (demodulation), and sends it to headphones or speakers to become sound waves. bcl3000
Due to the progress of science and technology, there are many radio waves with different frequencies in the sky. If all these radio waves are received, the audio signal will be like a busy city, with many sounds mixed together and nothing can be heard clearly. In order to try to select the desired program, there is a selection circuit behind the receiving antenna. Its function is to select the desired signal (radio station) and "filter out" the unwanted signal to avoid interference. This is the "channel selection" button we use when listening to the radio. The output of the selection circuit is the high frequency amplitude modulation signal of a selected radio station. It is impossible to directly drive headphones (electro-acoustic devices) with it, and it must be restored to the original audio signal. This recovery circuit is called demodulation. When the demodulated audio signal is transmitted to the earphone, the broadcast can be received. The simpl radio is called a direct detector, but that high-frequency radio signal obtain from the receiving antenna is usually weak, so it is not suitable for direct transmission to the detector. It is better to insert a high-frequency amplifier between the selection circuit and the detector to amplify the high-frequency signal. Even if a high-frequency amplifier has been added, the detected output power is usually only a few milliwatts, and it is ok to listen with headphones, but the speaker is too small, so an audio amplifier is added after the detected output to drive the speaker. High amplifier radio is more sensitive and powerful than direct detection radio, but its selectivity is still poor and its tuning is more complicated. The high-frequency signal received from the antenna is amplified by hundreds or even tens of thousands of times. There are generally several stages of high-frequency amplification, and each stage of the circuit has a resonant circuit. When a digitally displayed FM broadcast frequency is received,
When the frequency changes, the resonant circuit needs to be readjusted, and it is difficult to ensure that the selectivity and passband are exactly the same after each adjustment. In order to overcome these shortcomings, almost all radios now use superheterodyne circuits. The superheterodyne is characterized in that the carrier frequency of the selected high-frequency signal is changed to a lower fixed intermediate frequency (465KHz), and then amplified by an intermediate frequency amplifier to meet the detection requirements before detection. In superheterodyne receiver, in order to generate frequency conversion, there is an additional sine signal, which is usually called heterodyne signal. Circuits that generate heterodyne signals are customarily called local oscillations. There is an intermediate frequency difference between the local oscillator frequency of the radio and the frequency of the received signal, so the mixer and the selection circuit before the local oscillator adopt a unified tuning line, such as using coaxial double capacitors (PVC) for tuning, so as to keep the difference at a fixed intermediate frequency value. Because the intermediate frequency is fixed and the frequency is lower than the high frequency modulation signal, the gain of the intermediate frequency amplifier can be made larger, the work can be more stable, and the passband characteristics can be made ideal, so that the detector can obtain a signal large enough to make the whole machine output an audio signal with better sound quality. Commonly used radios are superheterodyne radios, mainly AM radios, FM radios and FM stereo radios. When a radio station plays a program, it first converts the sound into an audio signal through a microphone, and then modulates it with a high-frequency signal (carrier wave) after amplification. At this time, a certain parameter of the high-frequency carrier signal changes correspondingly with the audio signal, so that the audio signal we want to transmit is included in the high-frequency carrier signal, the high-frequency signal is amplified, and then when a high-frequency current flows through the antenna, a radio wave is formed and emitted. The propagation speed of radio waves is 3× 10 to the eighth power meter per second. This kind of radio wave is received by the radio antenna, then amplified and demodulated, restored to audio signals, and sent to the voice coil of the speaker, causing the corresponding vibration of the paper basin, so that the sound can be restored, that is, the process of acoustoelectric conversion transmission-electroacoustic conversion. The medium wave frequency (high frequency carrier frequency) is defined as 525- 1605 kHz (thousand cycles). The frequency range of short wave is 3500- 18000 kHz. Superheterodyne radio principle radio
The picture on the right is the working principle block diagram of am superheterodyne radio. The high-frequency signal received by the antenna and the local oscillation frequency of the radio station (its frequency is higher than the external high-frequency signal by a fixed intermediate frequency, and the China intermediate frequency standard stipulates that it is 465KHZ) are sent to the frequency converter for mixing conversion, and a new frequency is generated in the load loop (frequency selection) of the frequency conversion stage, that is, the intermediate frequency generated by the difference frequency (B in Figure 3-2). IF only changes the carrier frequency, but the original audio envelope does not change. It can better amplify the intermediate frequency signal, detect the intermediate frequency signal and filter out the high frequency signal (D in Figure 3-2). After low amplifier and power amplifier, the speaker is driven to sound. Brief introduction of the working principle of this machine. See Figure 3-3 for the circuit diagram of the antenna input loop composed of C 1. B 1。 VT 1。 B2 b 1。 C constitutes the frequency conversion stage. VT 1 is a frequency converter. The primary coil and c constitute the load of the frequency conversion stage. C 1。 B2 constitutes a local oscillation circuit, and C6 constitutes an oscillation coupling circuit, VT2. VT3 is an IF amplifier circuit, 2AP9 is a detection circuit, R9 is a volume potentiometer (with power switch), and C 16 is a high-frequency coupling capacitor. VT4。 VT5 is a Class B traction power amplifier composed of preamplifier and VT6.VT7. R 16. C2 1。 C 17 is the power wave circuit. r 1 . R2 . R3 . R4 . r5 . R6 . r7 . r 12 . r 10 . r 1 1 . r 13 . r 17 . r 18。
Can you receive A8 radio in Shenzhen? Is it a 45-degree Internet radio station? Thank you. Since it is a network radio station, you can listen to it online.
Telegraph A intercepted the telegram sent by B to C. Can C still receive the telegram? can
I just like the inner feelings of being a radio DJ. I also like it very much, especially following the music to rock and roll, forgetting all my troubles and showing my real music is the best!