In the sixties and seventies, radio was an important property of a family. Many middle school students and college students have to assemble their own radios. Just like today's students assemble computers, buy back a bunch of diodes, triodes, capacitors and resistors, and then assemble them according to the circuit diagram. Even the cover of the radio is made of plywood.
Electronic industry is a new industry developed in 1940s. Since the first five-year plan, the party and the state have successively established a number of key factories and scientific research units that produce electronic products. From 65438 to 0958, Shanghai Yin Hong Radio Equipment Factory, Tianhe Electrochemical Factory and Shanghai Institute of Radio Electronics Technology jointly developed the first transistor radio in China. Since then, some radio factories in Shanghai, Beijing and Nanjing have successively produced transistor radios such as "Spring Bud", "Le Fei" and "Red Light". One of the most famous is the "Panda" brand transistor radio produced by Nanjing Wireless Power Plant.
Who invented the transistor radio?
1844, the telegraph was invented, which can communicate with each other at a long distance, but it still depends on "wires" to connect. The reception and transmission of radio signals is "radio communication"; The whole history of the invention of radio communication is the result of research and invention by many scientists.
1888, German scientist heinrich hertz discovered the existence of radio waves.
1895 Russian physicist popov claimed that he successfully sent and received radio signals in two places 600 yards apart.
Later in the same year, Guglielmo Marconi, the son of a wealthy Italian businessman who was only 2 1 year-old, successfully launched his first launch on his father's manor land by radio waves.
1897, popov successfully communicated with the land platform on the naval cruiser with the wireless communication equipment made by himself.
Marconi sent radio waves to the other side of the Atlantic in 190 1 year.
1906, the Canadian inventor Fessenden made the first sound, and the radio broadcast began.
In the same year, American Reed forest invented the vacuum tube, which was the ancestor of vacuum tube radio. Since then, improved transistor radios (atomic particle radios) and transistor radios have appeared.
Why transistor radio?
Because the first commercial product of semiconductor transistor is transistor radio.
When the radio first appeared, it used vacuum tubes. Later, semiconductor transistors appeared, and the first commodity made by semiconductors was radios, so semiconductors became synonymous with transistor radios.
At the same time, it is also to distinguish between vacuum tube radio and transistor radio.
The principle of transistor radio
The basic working principle of radio Since people discovered that information can be transmitted by radio waves, they have continuously developed different methods to increase communication reliability, communication distance, miniaturization, power saving and light equipment. A receiver used to receive information, commonly known as a radio. At present, the radio can not only receive the radio, but also receive the TV set that can receive images and digital telegrams. With the development of broadcasting technology, radios are constantly upgrading. 1920 radio broadcasting has been developing for more than half a century. The radio has undergone three generations of changes: tube radio, transistor radio and integrated circuit radio, with more and more functions and higher quality. Since 1980s, radio has been developing towards the direction of circuit integration, digital display, stereo, function computerization and miniaturization.
When a radio station plays a program, it first converts the sound into an audio electrical signal through a microphone, and then modulates it with a high-frequency signal (carrier wave). 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, and the high-frequency signal is amplified again. Then, when the high-frequency current flows through the antenna, a radio wave is emitted outward, and the propagation speed of the radio wave is 3×108m/s. This radio wave is received by the radio antenna, then amplified and demodulated, and then restored to an audio signal, which is sent to the speaker voice coil to cause paper.
Directory of transistor radio development events
1923 65438+1On October 23rd, Americans set up China Radio Company to broadcast radio programs and sell radios. The United States produces the most radios, one of which is a crystal receiver and the other is an electron tube radio.
1953, China developed the first domestic radio ("Red Star" tube radio) and put it on the market.
1956, the first germanium alloy transistor in China was developed.
1958, the first domestic transistor radio was successfully developed in China.
1965, the output of transistor radios exceeded that of electron tube radios.
1980 is the peak period of the development of the radio market.
1982 saw the emergence of integrated circuit radios and radios with mixed circuits of silicon germanium tubes and audio output OTL circuits.
1985 to 1989 with the development of TV sets and tape recorders, the sales of transistor radios are declining year by year, and electron tube radios tend to be eliminated. The style of the radio has changed from a large desktop to a pocket radio. [Edit this paragraph] Broadcasting History192365438+1On October 23rd, American Osborne and China Zeng Jun founded China Broadcasting Corporation, which broadcasted radio programs for the first time in Shanghai and sold radios at the same time. There are more than 500 radios in the city, which are the earliest radios in Shanghai. Later, with the continuous establishment of radio stations, radios gradually appeared in Shanghai, all of which were imported, with the most produced in the United States. One of them is a crystal receiver, and the other is a tube radio. People like to use crystal receivers.
1In August, 924, the Ministry of Communications of Beiyang Government promulgated the Interim Provisions on the Installation of Radio Receivers, allowing citizens to install radios. There are more and more people installing radios, and the method is mostly to connect them with regenerative wires. In August of the same year, Yan Jingyang of Shanghai Jiande Savings Office successfully installed a radio by superheterodyne line connection. In June 65438+the following year 10, the crystal receiver and tube radio assembled by Yamei Radio Co., Ltd. in Songjiang Library were successful. They not only received radio waves from Shanghai Radio, but also received music programs from Japan Radio.
1in June, 1933, the crystal receiver 100 1 produced by Yamei Radio Co., Ltd. was small and beautiful in appearance, low in price and good in radio reception effect, and was welcomed by the public. 1June, 935, the company produced the first superheterodyne five-lamp radio with the model 165 1. The high-frequency and medium-frequency transformers, power transformers and coils used in this machine are all designed and manufactured by themselves except electron tubes and carbon resistors. Since then, a number of radio manufacturers have successively produced radios. Among them, Zhong Yong Wireless Motor Factory has a larger scale, second only to Yamei Radio Co., Ltd., which produces standard third-ring Yi Deng radios and DC three-lamp radios at 1936. In addition, there are Huachang Wireless Motor Factory and Yael Electric Co., Ltd., both of which have produced radios with one to five lights. Although the means of production are backward and the number of products is small, these products occupy a certain position in the domestic radio manufacturing industry.
From 65438 to 0936, with the development of radio broadcasting, radios were gradually popularized in the whole city, with a total of more than 65438+ million, but almost all of them were made abroad, which made the domestic national radio manufacturing industry develop slowly. 1937 In July, War of Resistance against Japanese Aggression broke out in an all-round way, and the Shanghai radio manufacturing industry was further hit. During the period of 1942, the Japanese invaders prohibited citizens from using radios with more than seven lights, and forcibly removed the short-wave coils of radios. Under the rule of Japanese puppet government, the production of radio manufacturers was at a standstill.
1945 after War of Resistance against Japanese Aggression's victory, Shanghai's national radio manufacturing industry resumed and a number of new radio manufacturing enterprises developed. By the end of 1947, there were 590 electrical industrial and commercial enterprises in Shanghai, including 235 radio industrial and commercial enterprises. In the same year, the National Government Resources Committee set up a research institute in Shanghai to make high-end eight-lamp radio with resource brand desktop and floor standing. However, bureaucratic capital enterprises imported a large number of complete sets of radio parts from abroad and sold assembled radios at low prices, which brought a new blow to the national radio manufacturing industry. By the eve of Shanghai's liberation, more than 30% of the factories in Shanghai's telecommunications industry were in a state of shutdown or semi-shutdown, and only seven factories and workshops were engaged in the manufacture of radios and their components, with *** 1 13 employees.