radio

Radio is a technology that is used for signal transmission and modulation by electromagnetic radiation (electromagnetic waves). These waves propagate across and through the air and can also travel through space vacuum, because these waves do not require the carrier medium (such as air molecules). The radio waves are a form of electromagnetic radiation, and is formed when electrically charged objects is modulated (increased frequency ) at a frequency that is found in radio frequency (RF) in an electromagnetic spectrum, and electromagnetic radiation move by electric and magnetic oscillations.

Toshiba G 810: The phone with a difference

Posted by Sylvia in October 6th 2009

under: Toshiba cell Phone Tags: 128MB RAM, 256MB ROM, 2G & 3G Networks, 3.15 MP camera, 8GB memory, cell phone, cell phone focus, cell phones, excel, microSD card slot, MP3 ring tones, PDF viewer, polyphonic ring tones, Power Point files, stereo FM radio, Toshiba, Toshiba cell Phone, Toshiba G 810, Toshiba G 810 cell phone, WAP 2.0, word

The Toshiba G 810 is a fantastic device for mobile communication. It comes with facility to provide you the opportunity for communication at both 2G & 3G networks for GSM 850/ 900/ 1800/ 1900 and HSDPA 850/ 1900/ 2100.

The phone measures 110×58x14mm and weighs 120 grams. The display of this phone is quite praiseworthy. The TFT resistive touch screen is fully performance oriented and displays 65K colors at 320×240 pixels resolution.

You can set the phone on vibration for receiving calls silently. This phone can also be set on downloadable polyphonic & MP3 ring tones.

The phonebook can include unlimited entries and fields. The photo call features is great for setting the phone on various pictures for the callers

Want a High Quality Radio? Sony Ericsson R306 Phone Unboxing Review

Plemix.com Joined: Apr 27, 2007 Posts: 114 PM, WWW

Posted: 2008-10-02 11:16 Want a high quality radio? Go for Sony! Sony’s radios have a long history of excellent clarity, durability and speed. The R306 Radio integrates the excellent radio and packs a lot more features in a compact body. Is it for you radio lovers? Read on! The package contains the phone, a battery, a handsfree, a charger and a user’s guide. The R306 Radio has a pretty long battery life (9 hours talk, 410 hours standby) so there is no need of a secondary battery (at least for most of us). When it comes to design, the R306 Radio is not the type that can instantly inspire the wow’s but its design is not too bad either. The body has a moderate 15.8mm thickness, which is about average for a budget flip phones. The phone is also large enough to fit in your palm securely. The interior design is simple with a lot of black and silver. The 1.9” screen does not have the most vibrant color or highest resolution, but it does a decent job for displaying text. The keys have a nice tactile feeling with about the right softness. The keys are about the size of your fingertips. I believe Sony Ericsson could have made the keys larger by using square instead of rounded keys. The camera has 1.3MP with no flash or autofocus. Photo quality is comparable to other 1.3MP, or some 2MP cameras with accurate exposure but suffers from noise and inaccurate focus. See the AM word on the handsfree? Most phones or MP3 players can’t handle AM frequencies but the R306 Radio has no problem with them! You need to have the handsfree plugged in to use the radio function. The front aluminum plate has 5 buttons for controlling the FM/AM radio. Beneath the plate lies a hidden display that can display the channel you are on. Besides the usual phonebook and organizers, it can record a section of the music and return the track title to you through the TrackID feature. The biggest selling point of the R306 Radio is the design and the high-quality radio. Battery life is pretty good and the external keys and display are very convenient. The only real complaint is the mediocre feature set, which is the common problem of budget models.

If you listen to conventional wisdom you might think the traditional bedside clock radio was on its way out, since in many homes cell phones now rouse the sleeping from their beds. But a new gadget from Sony seeks to keep alarm clocks on the night table while bringing convenience to cell phone users.

The ICF-C8WM, unveiled on Wednesday at the IFA electronics fair in Berlin, is an LCD bedside clock radio with cell phone dock.

A large digital clock occupies the center of its round face, and a Sony Ericsson cell phone or Walkman can be plugged into a connector on the right-hand side of the device.

This not only charges the phone, replacing the charger and cable that many keep next to their bed, but also means it's possible to wake up to music stored on the handset. For those who use their cell phones as music players this could be a good thing.

Sometimes laptop is more than just a device. Using laptops over years, some of us tend to develop a genuine affection toward their little (or not so little) companions. We take care of them, putting them in a nice hand-made fabric, spicing them up with some fancy outfit and providing them with a personality using laptop skins. That’s not as bad as it sounds, and there are many ways to use laptop decoration (or laptops decorated by other people) as a source of inspiration. In some way you may also call it laptop art.

In this issue of monday inspiration series we provide you with some fresh ideas to spice up your environment with laptop skins, engravings, sleeves, cases and stickers. In the end of this post you’ll also find some experimental ideas for laptop decoration — caution, you don’t really want to replicate them at home or at office — well, at least if you care about your laptop.

Apparently, Apple geeks are far more emotional when it comes to accessories for their laptops — although we’ve tried to cover as many different ideas as possible, in the selection below many of the presented ideas are used on Macs. There is nothing we can do about it, really.

Laptop Skins and Engravings

Shalgo Laptop Designs
This Dutch company offers a number of the so-called mozaikits which you can place not only on your laptop, but also, for instance, on walls. Stylish.

Awesome Designer Laptops
Well, these are indeed… unusual. And it is damn hard to make something like this on your own.

HP Pavilion dv2800t Artist Edition
An artsy laptop manufactured by Hewlett-Packard.

Computerlicious Designer Laptops
Engadget shows off some pretty beautiful designer laptops, decorated with fabric and leather.

MacBook skin
In most cases you can use your own skin designs and let some skin printing store print them out for you. That was the case here.

Apple Art
Stylish. And pretty cool.

GelaSkins
Here you’ll find some artistic laptop skins (art, design, typography etc.)…

Schtickers.com
…even more various laptop skins.

Radio adalah teknologi yang digunakan untuk pengiriman sinyal dengan cara modulasi dan radiasi elektromagnetik (gelombang elektromagnetik). Gelombang ini melintas dan merambat lewat udara dan bisa juga merambat lewat ruang angkasa yang hampa udara, karena gelombang ini tidak memerlukan medium pengangkut (seperti molekul udara).

Daftar isi [sembunyikan] 1 Gelombang radio 2 Penemuan gelombang radio 3 Penggunaan radio 4 Lihat pula 5 Pranala luar

[sunting] Gelombang radio

Frekuensi gelombang radio untuk pengiriman suara

Gelombang radio adalah satu bentuk dari radiasi elektromagnetik, dan terbentuk ketika objek bermuatan listrik dimodulasi (dinaikkan frekuensinya) pada frekuensi yang terdapat dalam frekuensi gelombang radio (RF) dalam suatu spektrum elektromagnetik, dan radiasi elektromagnetiknya bergerak dengan cara osilasi elektrik maupun magnetik.

Gelombang elektromagnetik lainnya, yang memiliki frekuensi di atas gelombang radio meliputi sinar gamma, sinar-X, inframerah, ultraviolet, dan cahaya terlihat.

Ketika gelombang radio dipancarkan melalui kabel, osilasi dari medan listrik dan magnetik tersebut dinyatakan dalam bentuk arus bolak-balik dan voltase di dalam kabel. Hal ini kemudian dapat diubah menjadi signal audio atau lainnya yang membawa informasi.

Undang-undang Nomor 32 Tahun 2002 Tentang Penyiaran menyebutkan bahwa frekuensi radio merupakan gelombang elektromagnetik yang dipergunakan untuk penyiaran dan merambat di udara serta ruang angkasa tanpa sarana penghantar buatan, merupakan ranah publik dan sumber daya alam terbatas. Seperti spektrum elektromagnetik yang lain, gelombang radio merambat dengan kecepatan 300.000 kilometer per detik. Perlu diperhatikan bahwa gelombang radio berbeda dengan gelombang audio.

Gelombang radio merambat pada frekuensi 100,000 Hz sampai 100,000,000,000 Hz, sementara gelombang audio merambat pada frekuensi 20 Hz sampai 20,000 Hz. Pada siaran radio, gelombang audio tidak ditransmisikan langsung melainkan ditumpangkan pada gelombang radio yang akan merambat melalui ruang angkasa. Ada dua metode transmisi gelombang audio, yaitu melalui modulasi amplitudo (AM) dan modulasi frekuensi (FM).

Meskipun kata 'radio' digunakan untuk hal-hal yang berkaitan dengan alat penerima gelombang suara, namun transmisi gelombangnya dipakai sebagai dasar gelombang pada televisi, radio, radar, dan telepon genggam pada umumnya.

[sunting] Penemuan gelombang radio

Dasar teori dari perambatan gelombang elektromagnetik pertama kali dijelaskan pada 1873 oleh James Clerk Maxwell dalam papernya di Royal Society mengenai teori dinamika medan elektromagnetik (bahasa Inggris: A dynamical theory of the electromagnetic field), berdasarkan hasil kerja penelitiannya antara 1861 dan 1865.

Pada 1878 David E. Hughes adalah orang pertama yang mengirimkan dan menerima gelombang radio ketika dia menemukan bahwa keseimbangan induksinya menyebabkan gangguan ke telepon buatannya. Dia mendemonstrasikan penemuannya kepada Royal Society pada 1880 tapi hanya dibilang itu cuma merupakan induksi.

Adalah Heinrich Rudolf Hertz yang, antara 1886 dan 1888, pertama kali membuktikan teori Maxwell melalui eksperimen, memperagakan bahwa radiasi radio memiliki seluruh properti gelombang (sekarang disebut gelombang Hertzian), dan menemukan bahwa persamaan elektromagnetik dapat diformulasikan ke persamaan turunan partial disebut persamaan gelombang.

[sunting] Penggunaan radio

Sebuah radio merek Bush lama

Banyak penggunaan awal radio adalah maritim, untuk mengirimkan pesan telegraf menggunakan kode Morse antara kapal dan darat. Salah satu pengguna awal termasuk Angkatan Laut Jepang memata-matai armada Rusia pada saat Perang Tsushima di 1901. Salah satu penggunaan yang paling dikenang adalah pada saat tenggelamnya RMS Titanic pada 1912, termawuk komunikasi antara operator di kapal yang tenggelam dan kapal terdekat, dan komunikasi ke stasiun darat mendaftar yang terselamatkan.

Radio digunakan untuk menyalurkan perintah dan komunikasi antara Angkatan Darat dan Angkatan Laut di kedua pihak pada Perang Dunia II; Jerman menggunakan komunikasi radio untuk pesan diplomatik ketika kabel bawah lautnya dipotong oleh Britania. Amerika Serikat menyampaikan Empat belas Pokok Presiden Woodrow Wilson kepada Jerman melalui radio ketika perang.

Siaran mulai dapat dilakukan pada 1920-an, dengan populernya pesawat radio, terutama di Eropa dan Amerika Serikat. Selain siaran, siaran titik-ke-titik, termasuk telepon dan siaran ulang program radio, menjadi populer pada 1920-an dan 1930-an.

Penggunaan radio dalam masa sebelum perang adalah pengembangan pendeteksian dan pelokasian pesawat dan kapal dengan penggunaan radar].

Sekarang ini, radio banyak bentuknya, termasuk jaringan tanpa kabel, komunikasi bergerak di segala jenis, dan juga penyiaran radio. Baca sejarah radio untuk informasi lebih lanjut.

Sebelum televisi terkenal, siaran radio komersial termasuk drama, komedi, beragam show, dan banyak hiburan lainnya; tidak hanya berita dan musik saja. Lihat pemrograman radio.

[sunting] Lihat pula

• Daftar stasiun radio
• Daftar stasiun radio di Indonesia
• Radio komunitas
• Daftar radio komunitas
• Amatir Radio (ORARI)
• Radio Antar Penduduk / Citizen Band (RAPI)