How is the data put on radio waves?

Hi all..to make my blog updated, since i am quit busy with my study schedules, i have tried to copy some informative page for visitors eyes regarding how is the data travel through waves. Maybe a lot of us still do not know how the data that we send everyday (voice, cw) work with waves including me until i found this article.
There are two common ways to put information in a radio wave, and you've likely run into them yourself. They are called A.M. and F.M. just like the two choices you've always known are on a radio. To understand these two ways of sending information it is important to know that radio waves, by themselves, have very regular patterns. Generally they keep the same amplitude or frequency all the time. (Amplitude is the "height" of the radio wave, frequency is how close the waves are to each other.)






A.M. stands for amplitude modulation. In this method, the information is put into a radio wave by varying the amplitude. For example, if all we wanted to do was send 1's and 0's, we could have just two different levels of amplitude that correspond to these numbers--1 being high, 0 being low.



F.M. stands for frequency modulation. This time the amplitude is kept constant, it is the frequency that is varied..



So ladies and gentleman, see how beauty and brilliants the creator up there..Think about it..Until then, see u in next post..73

Cerita Ghairah: Liana Memalukan Keluarga

"Sungguh memalukan!!"

"Maafkan saya bapak, sa..saya..saya menyesal!", Liana terisak-isak di hadapan bapaknya.

"Menyesal ? Dah terlambat! Kau tahu tak? Nama keluarga kita dah tercemar! … belum pernah keturunan kita kena macam nie? Kau tahu tak!" herdik bapak Liana.

"Sudahlah bang", mak Liana menyampok, "Kita bincangkan sekeluarga."

"Nak bincang aper lagi? … anak awak nie dah mengaku… … issshhh… … ." balas bapanya sambil memalingkan mukanya ke arah pokok di luar.

Liana betul betul menyesal dgn pengakuannya itu… kalau dia tahu bapaknya jadi camnie dia diam je… toksah mengaku lagi baik. Seluruh hidupnya seakan-akan runtuh di depan matanya, masa depan dia gelap? … dia telah mencemarkan nama baik keluarga dan keturunannya. Dia tahu masyarakatnya tidak akan dapat menerima dia lagi. Dia tahu keluarganya dah kecewa. What a letdown?

Di satu pagi yg hening dia keluar berjalan ke arah satu bangunan pencakar langit yg tinggi. Perlahan-lahan dia menaiki tangga sampai ke atas bumbung bangunan itu. Dia memandang ke bawah… dia lihat kereta dan org ramai bersepah kat bawah macam semut-semut yg baru kena spray dgn Baygon.

Liana dah nekad apa terjadi… . jadilah… .. Dia dah memalukan keluarganya, dia mencemarkan keturunannya, bapanya tidak mahu menerima atas kelemahannya itu.

Liana tebayangkan wajah maknya, air matanya menitis. Emaknya lah tempat dia bermanja, emaknya la yg akan meyelimutkan dikala sejuk, menyuapkan dikala lapar, wajah adik-beradik kembarnya juga terbayang dimata.

Sambil mengesat airmatanya, dia menarik nafas panjang… berjalan kehadapan hingga ke hujung bangunan itu. Setapak demi setapak dia melangkah ke hadapan hingga dirinya terjatuh melayang ke bawah… dia dapat rasakan angin yg begitu deras memukul mukanya… jantungnya berdegup pantas bila dia melihat bumi semakin dekat… .. dgn satu tarikan nafas yg dalam, Liana mengembangkan sayapnya, SWOOOOOSSSSHHHHHHHHH!!!… … .. dia terbang .

"Yessss! Yessss! Yessssssssssssssss! I’ve made it!!!!!", dia memekik keriangan.

Finally dia dapat melawan fobianya… dia dah no longer afraid of height… sebagai seekor burung, itulah yg sepatutnya menjadi fitrah semulajadi… selama ini dia takut… .. ye dia takut pada tempat tinggi dan kerana ketakutan inilah membuatnya tidak mahu terbang… dah bertahun dia rahsiakan hal ini dari keluarganya… . Sebab tu bapak dia kecewa bila dia membuat pengakuan itu kerana memang tak pernah seumur hidup seekor burung takut pada ketinggian.

Tapi sekarang dia dah tak takut, dia dah berani… . dia dah boleh terbang…

Arrival of Radio Operators from Mersing to Pengkalan Balak

Attention to all hams..
Member from Mersing will be arrived at Pengkalan Balak (RAE 2009/2) as followed:

Date: 15th December 2009
Time: Evening
Venue: Permata Chalet, Pengkalan Balak
Monitoring Frequency: 9M4RKA (Melaka area, vee99 (144.990-Masjid Tanah area.
Number of members: 10 families.
Time for Eyeball: 9.00pm-12pm

Therefore, to celebrate their arrival, i invite all hams to gather on the night of 15th December at Permata Chalet, Pengkalan Balak.

Friendship

Hi all..So long not to update my blog with my own word. Usually to make my blog update i use to copy any informative page from any other website for visitors eyes. However i do believe that those friends who ever visit here perhaps may get something from my post. Today i would like to write about friendship. The word that i really appreciate it when i realized how beauty the world is. Friendship isn't always easily described. The Eskimos, they say, have a hundred different words for snow. Unfortunately, the English language isn't quite as innovative, though it has vast opportunities to differentiate meaning. Certainly, Love is one of those opportunities. And so, too, is Friendship.

Instead of different words, however, we're stuck with simple adjectives. Close friend. Best friend. Childhood friend. Intimate friend. Trusted friend. Beloved friend. But whether you use adjectives or different words, few could deny the nearly infinite meaning in such a simple word.

Friends are special people. We can't pick our family, and we're sorely limited in the number of them at any rate. Society and mores (and often our own conscience) dictate we select a single mate. But our friends can be as diverse and infinite as the adjectives we choose. Our friends, in a very real sense, reflect the choices we make in life. So since we get involve in amateur radio as a hobby, of course we meet a lot of friends. Therefore, appreciate them as we appreciate our self. Until then..73

Radio Regions of the World

The International Telecommunication Union (ITU) divides the world into three radio regions. Frequency allocation to different radio communication services differ from region to region

What is "Skip Zone"?

Under the action of solar radiation and the hail of meteorites, an ionized layer is formed in the upper part of the Earth's atmosphere. In this layer, the neutral air molecules are decomposed into ions and electrons and the whole layer presents a chaos of charged particles.Short wave radio signals are reflected from this layer just as light rays are reflected from the surface of a mirror, or sound from a barrier.Likewise, this layer can be compared with the edge of billiard table: if the ball does not go straight into the pocket, it can be sent on rebound. In a situation, a radio receiver set located at a distance of 200 kilometres (say) away from the wireless transmitting station can not receive signals from the transmitting station. This is because the ground waves are stopped by the Earth's curvature and the sky wave will not reach the receiver, because it bounces again more than 200 kilometres way. So some 'blind zones' are formed and if the receiver is located in that blind zone it will receive no signal or very weak signal. In such a situation, another station can relay the message to the target station. The distance of the intended receiver from the transmitter is then termed as 'skip distance'. So it is not always necessary that a receiving station located nearer (than a station located further away from the transmitting station) to the transmitting station will be able to receive its signal.

IONOSPHERIC PROPAGATION

The First proclaimed Radio Amateur (HAM), Guglielmo Marconi was not using VHF or UHF for his famous Trans-Atlantic radio communication experiment nor was he employing any artificial relay mechanism. Yet his radio signal traveled half the world. Marconi's wireless transmitter powered by 2,000 volts from a generator driven by a 32 horsepower petrol engine pumped out 25,000 watts (25 KW) of power at a carrier frequency of about 328 kHz (Kilo Hertz). Alternately. the wavelength of the radio frequency used was approximately 915 metres. The formula to calculate wavelength of an electromagnetic wave is Wavelength in metres = 300/frequency In Mega Hertz. The dial of a radio receiver also marks either wavelength or frequencies or both.
On frequencies below 30 MHz, long distance radio communication is the result of refraction (bending) of the wave in the ionosphere. Oliver Heaviside in England and A.E. Kennally in America,in 1902, suggested that there must be some kind of reflecting medium in the upper atmosphere that caused the radio waves to be returned to Earth at considerable distances from the transmitter. Under the action of solar radiation and the hail of meteorites, an ionised layer is formed in the upper part of the Earth's atmosphere. In this layer, the neutral air molecules are decomposed into ions and electrons and the whole layer presents a chaos of charged particles.
Short wave or High Frequencies (HF) in the range of 3-30 MHz propagates through this invisible layer which consists of charged particles located at altitudes of between 250 and 400 km in the atmosphere surrounding the Earth. This layer of charged air particles called F2 layer of the ionosphere plays a vital role in HF propagation by reflecting or refracting the HF signals back to Earth.
The ionosphere has got different sub-layers. The lowest is D-layer at altitudes ranging from 50 to 90 km. High frequencies (3-30 MHz) penetrate this layer, while low frequency (LF: 30-300 kHz) or medium waves are absorbed by this layer. To some extent LF and Very Low Frequency (VLF: 3 to 30 kHz) are reflected during daytime. It slightly scatter and absorbs HF. This layer subsists only during daytime.
The E-layer extends from an altitude of 100 km. Though sunlight is an important factor for its existence, after sunset also it exists for some time. This layer is responsible for evening and early night time propagation of medium waves (low frequency) upto a distance of about 250 km. Propagation of lower short wave frequencies, e.g. 2 MHz , up to distance of 2000 km at daylight time is due to this layer. It has little effect at night.
F1 layer exists at an altitude of 200 km during daytime and its characteristics are very similar to E-layer which emerges into F2 layer at night. F2 layer is the most important layer which exists at altitudes ranging from 250 to 400 km and HF long distance propagation round the clock is due to this layer. The behaviour of this layer is influenced by the time of the day, by season and by sunspot activity. F2 layer was formerly known as Appleton layer. This layer has a high ionization gradient. This layer exists both in the daytime and nighttime. Since at such an altitude air density is extremely low, the free ions and electrons (due to the action of ultraviolet radiation from the Sun) can not recombine readily and so can store energy received from the Sun for many hours; that is the reason the refractive property of this layer changes only to a negligible extent during day and night. The path which the short wave signal follows through the F2 layer is in reality a curved one. Degree of the curve depends on the angle of incidence of the wave, ionization gradient of the layer and frequency of the signal.