Radio is a powerful wireless medium of communication. It sends and receives information using electromagnetic waves. In the late nineteenth century, a scientist from many countries discovered radio at the same time but GUGLIELMO MARCONI was considered a radio wave detector. In the past, it only used on the radio but now this wireless technology is using everywhere. The radio wave is the principle of any wireless communication including radio, television, mobile phone, etc. The radio telescope is also used to monitor space using radio waves.
History of BD radio
16 December 1939 Bangladesh radio began broadcasting first time named as Dhaka broadcasting center ( ঢাকা ধ্বনি বিস্তার কেন্দ্র ). The broadcasting house was built by renting the house of Nazimuddin road at present which is the building of Shaikh Burhanuddin college. In Kalyanpur a 5 mediumwave transmitter had a broadcast limit of 20-25 miles at night and 30-45 miles a day. Now the transmitter is stored on the radio museum. Dhaka Betar as Dhaka center of All India Radio continued developing the culture of this region. Many artists, poets, writers, journalists, playwriters songwriters, composers, presenters, singers, instrumentalists,actors-
There was no air conditioning system in the broadcasting house even a single sound recording device. For this, the program of the artist was broadcasted live. Two notable live performances from the Dhaka center were Pramothesh Barua and JAMUNA Debi starring drama Devdas and music Purbani written and directed by rebel poet Kazi Nazrul Islam. That time the session was held from 5 pm to 10 pm.
After partition, the Dhaka betar first operated as a Pakistan broadcasting Service and later a radio Pakistan station. In 1954, 2 one kilowatt medium wave transmitters and 1959 one kilowatt mediumwave transmitter at Kalyanpur were installed. In February 1960 Dhaka betar was shifted to Shahbagh a modern broadcasting house including 6 studios. This broadcasting house now headquarters of Bangladesh Betar. In 1952 the Betar staff artists refrain from broadcasting the program on February 20-24, protesting the shooting of students and students in Bayanno Language Movement. 7th March 1971 the ban on the speech of Bangabandhu racecourse to promotion on wireless broadcasting, all staff, and artists of Betar took place on the highway. The next morning, when the Pakistani military authorities agreed to broadcast Bangabandhu's speech, the radio staff reopened the radio station. In the liberation war 1971, this radio station played a vital role. During the war, it was known as Independent Bangla Betar Center. The radio station was shifted several times due to heavy ammunition. It was finally removed to Calcutta on March 25, from where the program was broadcast for the rest of the war. On December 6, the radio station was renamed Bangladesh Betar.
Present BD radio
Bangladesh Betar is a state-owned company in Bangladesh. From 1975-1996 it was known as Radio Bangladesh. Now the headquarter of Bangladesh Betar is in Shahbagh. It is now broadcast, retained, edited and archived by 12 studios from every morning from 6 am tonight 2:30 am including commerce, extraterrestrial, transportation and traffic broadcasts. From its inception, Bangladesh Betar has become a major source of information, education, and entertainment with its low budget, easy-to-carry and content-rich presentation to people of all ages.
After Independence, Dhaka was upgraded from the regional center to the national radio station. The responsibility of creating and broadcasting new programs for the needs of the nation has increased manifold. Periodically, broadcasting activities are enhanced through the information of extraterrestrial, transcription, agriculture, trade, monitoring, music, education, audience research, population, health and nutrition, and traffic broadcasting units. Now Bangladesh Betar has 71 studios, 15 mediumwave, 3 short-wave and 12 FM transmitters for radio program talkers and publicists. And planning has 12 FM transmitters to establish in the future.
At present all the stations and units of Bangladesh Betar are broadcasting a total of 225 hours daily. Above all 65% is the musical program. Bangladesh Betar produces and promotes 600 dramas per year, an average of about 12 plays a week on a weekly basis. One hour of commercial activities in 1963 of Dhaka center has now been extended 17 hours daily through all radio stations. Apart from this radio farming activities last for 4 hours and 30 minutes, 2 hours for transcription, 8 hours for population, health and nutrition activities, 8 hours for traffic broadcasting, 6 hours for children and woman development activities, and education activities 12 hours. Everyday 67 news bulletin, 2 news review and a newsreel are broadcast wirelessly. The monitoring directorate monitors the broadcast of 25 radio news and current events abroad and sends a report daily to headquarter.
In Bangladesh, there are 2750 posts including 664 class positions. There are currently 11000 staff and artists listed on the radio. Bangladesh Betar is a full member of the Asia Pacific Broadcasting Union (ABU), the Asia Pacific Institute for Broadcasting Development (AIBD) and the Commonwealth Broadcasting Association (CBA) and an associate member of the broadcasting organization of non aligned countries ( BANAC)and the Islamic States Broadcasting Organisation. As the Government of Bangladesh allow FM broadcasting in the private sector 6 commercial FM station have a started functioning. These stations are radio today, radio fourth, ABC radio, radio AM, Dhaka FM, and people's radio. These are mainly City Centric like Dhaka, Khulna, Bogra,Sylhet Cox's Bazar and Chittagong. The stations broadcast lively recorded songs and lively news bulletins in their respective productions.
Sir Jagadish Chandra Bose
Sir Jagadish Chandra Bose was polymath, biologist, physicist, biophysicist, archaeologist and an early writer of science fiction. J.C.Bose was Pioneer in the field of microwave devices. He is born on 30 November 1858 Bikrampur, Munshiganj, Eastern part of British India ( present Bangladesh). In 1885 took up a job as an Assistant Professor of Physics at Presidency College, the oldest college in Calcutta. In this time JC Bose faced racism at the workplace: the salary differential between Indians and British was 3X! He started a silent protest against this horrible system by refusing to accept the lower salary for three years, and in the fourth year, he was finally paid in full, including the arrears salary from his job of starting. In 1896 he showcased a transmission on a town hall of Calcutta. The transmission was for a distance of 75 feet passing through was to remotely ring a bell and explode some gunpowder. He has invented mercury coherer attached to a telephone detector and is still showcased Kolkata University's Science College.
To build an operational two-way radio Guglielmo Marconi used a coherer-a radio wave receiver. Which is used to detect the radio frequency signals that the antenna picks up? The coherer converts a radio signal to a direct current signal which the powers an earphone or a morse printer by which humans can hear or see the signal. Marconi's coherer is known to be an exact copy of Bose's coherer. JC Bose did not agree to apply for a patent because he believed in free follow of inventions in the field of science. But due to the influence of his American friends he had applied for the patent in 1901. US patent was awarded to him in 1904. The Institution of Electrical and Electronic Engineer (IEEE) named him as the 'father of radio science' in 1997.
J.C.Bose is also said to be the first Indian biophysicist and even the first Indian modern scientist. In fact, his work on radio and wireless communication effectively make him the father of modern Wi-Fi. JC Bose was more recognized because of a machine called "crescograph", a device for measuring growth in plants. His contribution was within in many other places. Still in the name of invention of radio people only know Marconi's name where a huge contribution of coherer in radio. Without the coherer invention of radio was impossible that time which was invented by Sir Jagadish Chandra Bose. JC Bose never believed to use his invention in commercial way. He faced many racism in his life but always wanted to spread his work for human welfares.