Curiosity : Something behind TV and Radio

Watching TVWhile watching TV or Listening to FM Radio, what we do? We switch between channels/stations which in fact is tuning the frequencies  of  electromagnetic spectrum which are measured in Hertz (Hz). By the way who regulates this? What frequency is used for what purpose? Is there any standards? Know more now…

Radio spectrum refers to the part of the electromagnetic spectrum corresponding to radio frequencies – that is, frequencies lower than around 300 GHz. Electromagnetic waves in this frequency range, called radio waves, are used for radio communication and various other applications.

So, your TV or Radio Stations produce the radio waves which you receive and enjoy.

Who can generate the Radio waves? Who controls it? 

The generation of radio waves is strictly regulated by the government in most countries, coordinated by an international standards body called the International Telecommunications Union (ITU). Different parts of the radio spectrum are allocated for different radio transmission technologies and applications. In some cases, parts of the radio spectrum is sold or licensed to operators of private radio transmission services (for example, cellular telephone operators or broadcast television stations). Ranges of allocated frequencies are often referred to by their provisioned use (for example, cellular spectrum or television spectrum)

Flag of ITU.svgITU is a specialized agency of the United Nations (UN) that is responsible for issues that concern information and communication technologies. The ITU coordinates the shared global use of the radio spectrum, promotes international cooperation in assigning satellite orbits, works to improve telecommunication infrastructure in the developing world, and assists in the development and coordination of worldwide technical standards. The ITU is active in areas including broadband Internet, latest-generation wireless technologies, aeronautical and maritime navigation, radio astronomy, satellite-based meteorology, convergence in fixed-mobile phone, Internet access, data, voice, TV broadcasting, and next-generation networks.

ITU, based in Geneva, Switzerland, is a member of the United Nations Development Group. Its membership includes 193 Member States and around 700 Sector Members and Associates.

Okay, what are the frequencies or wave lengths used by our Televisions? What about our mobile phones?

Well, the ITU regulates it along with governments of various countries and allocates the frequencies as bands, for various purposes. The list below will explain the typical allocation.

band is a small section of the spectrum of radio communication frequencies, in which channels are usually used or set aside for the same purpose. Above 300 GHz, the absorption of electromagnetic radiation by Earth’s atmosphere is so great that the atmosphere is effectively opaque, until it becomes transparent again in the near-infrared and optical window frequency ranges.

To prevent interference and allow for efficient use of the radio spectrum, similar services are allocated in bands. For example, broadcasting, mobile radio, or navigation devices, will be allocated in non-overlapping ranges of frequencies. Each of these bands has a basic bandplan which dictates how it is to be used and shared, to avoid interference and to set protocol for the compatibility of transmitters and receivers.

Band name Abbreviation ITU band Frequency
and
wavelength in air
Example uses
Tremendously low frequency TLF   < 3 Hz
> 100,000 km
Natural and artificial electromagnetic noise
Extremely low frequency ELF   3–30 Hz
100,000 km – 10,000 km
Communication with submarines
Super low frequency SLF   30–300 Hz
10,000 km – 1000 km
Communication with submarines
Ultra low frequency ULF   300–3000 Hz
1000 km – 100 km
Submarine communication, Communication within mines
Very low frequency VLF 4 3–30 kHz
100 km – 10 km
Navigationtime signals, submarine communication, wireless heart rate monitorsgeophysics
Low frequency LF 5 30–300 kHz
10 km – 1 km
Navigation, time signals, AM longwavebroadcasting (Europe and parts of Asia),RFIDamateur radio
Medium frequency MF 6 300–3000 kHz
1 km – 100 m
AM (medium-wave) broadcasts, amateur radio, avalanche beacons
High frequency HF 7 3–30 MHz
100 m – 10 m
Shortwave broadcasts, citizens’ band radio, amateur radio and over-the-horizon aviation communications, RFIDOver-the-horizon radarAutomatic link establishment (ALE) /Near Vertical Incidence Skywave (NVIS) radio communications, Marine and mobile radio telephony
Very high frequency VHF 8 30–300 MHz
10 m – 1 m
FMtelevision broadcasts and line-of-sight ground-to-aircraft and aircraft-to-aircraft communications. Land Mobile and Maritime Mobile communications, amateur radio,weather radio
Ultra high frequency UHF 9 300–3000 MHz
1 m – 100 mm
Television broadcasts, Microwave oven,Microwave devices/communications, radio astronomymobile phoneswireless LAN,BluetoothZigBeeGPS and two-way radios such as Land Mobile, FRS and GMRSradios, amateur radio
Super high frequency SHF 10 3–30 GHz
100 mm – 10 mm
Radio astronomy, microwave devices/communications, wireless LAN, most modern radarscommunications satellites, satellite television broadcasting,DBS, amateur radio
Extremely high frequency EHF 11 30–300 GHz
10 mm – 1 mm
Radio astronomy, high-frequencymicrowave radio relay, microwave remote sensing, amateur radio, directed-energy weaponmillimeter wave scanner
Terahertz orTremendously high frequency THz or THF 12 300–3,000 GHz
1 mm – 100 μm
Terahertz imaging – a potential replacement for X-rays in some medical applications, ultrafast molecular dynamics,condensed-matter physicsterahertz time-domain spectroscopy, terahertz computing/communications, sub-mm remote sensing, amateur radio

Courtesy : Wikipedia and ITU

Do you want to know about anything in a simpler and understandable way? Please drop a comment about it on any of our posts. We will get back on that in our future posts.

Remember? : “Amul Surabhi” – a popular TV Show

That was not an era of the Internet, even mobile phones were high-tech machines that time. Doordarshan channel and the classic Antenna were the main entertainment in India. I am talking about the 90’s.

One show in particular invaded the hearts of millions that time. Do you remember the TV show “Amul Surabhi”? People who used to watch Doordarshan in the 90’s must recollect the vivid memories of this wonderful programme

I was a school kid that time look eagerly for the Tamil version of the show, I think Wednesday night 10pm guess I am not wrong. There were no discovery channel or travel & living channel to take us places. This show was like an explorer for many kids and elders that time. Sometimes we curse DD if they miss out the dubbed version and telecast the Hindi one. Sad that time I am not familiar with ABCs of Hindi 🙂 I have vivid memoir of those days. Wanted to know is there anyone who still remembers this wonderful Surabhi? Please comment with your experience.

surabhiSurabhi (English: Fragrance) was a popular Indian cultural magazine show hosted by Renuka Shahane and Siddharth Kak, which ran from 1993 to 2001. It was telecast on Doordarshan, the Indian state-run television channel, and later moved to Star Plus on Sunday mornings. Surabhi was produced by Kak’s Mumbai based production house Cinema Vision India and had Indian culture as its central theme. The show holds the distinction of being India’s longest-running cultural series and features in the Limca Book of Records for receiving the largest measured audience response ever in the history of Indian television.

The title music of Surabhi was composed by acclaimed Indian composer and classical violinist Dr. L. Subramaniam. Indian cooperative dairy giant Amul sponsored it for a long time, and the show was titled Amul Surabhi. The show had a rating of 51 percent in its initial run in 1993.

One of the reasons of its popularity was the weekly quiz open for viewer participation. At that time mobile phones and Internet were not prevalent in India and viewers would post their responses using the 15 paise postcard of India post. According to the Limca Book of Records the show once received the highest ever documented response in the history of Indian television – over 1.4 million letters in a single week. The Indian postal department was forced to issue a different category of postcards called “Competition Postcards” priced at 2 Rupees each for participating in such contests. Surabhi was dubbed in Indian regional languages like Tamil and got a great response from Indian states where Hindi is not an official language.

During the 1990s, Surabhi had become a benchmark show and is known as “one of the best television shows ever made that reflected the length and breath of the Indian culture“. Subsequently, Kak established the Surabhi Foundation with the assistance of Ford Foundation and started a project on preserving cultural artifacts.

AR Rahman’s rare interview on Surabhi

View more episodes here  on Amul TV

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Courtesy : Wikipedia, Amul.TVEpisode Details

Sunday Stuff : What China Makes? (top 10 infographic)

THINGS_CHINA_MAKES_INFOGRAPHIC_IBT

China makes everything and makes a lot of it. Here are 10 things that China makes so much of that if production stops, consumers across the globe will find themselves missing out on certain creature comforts.

Not that China will stop production soon. In July, the manufacturing sector went against projections of a contraction, with the Purchasing Managers’ Index going up to 50.3 that month instead of dropping to 49.8 as forecast initially. A PMI of below 50 indicates contraction while a number above 50 means expanding activity. June PMI was 50.1. August PMI is expected to climb to a three-month high of 50.6.

The optimism for the manufacturing sector naturally carries through to exports as production is heavily geared toward the latter. In Global Sources’ recent supplier survey, for instance, more than 70 percent of respondents expect higher export revenue in the second half of 2013.

This infographic is designed by Lisa Mahapatra and was originally published at the International Business Times.

Courtesy & Source : International Business Times.