My Seventh Lesson with Ms. Noor Azura

Date : 13th September 2009 (Sunday)

Time : 11.00am-12.30pm

Place : DKG 3/9, UUM

Today, lecturer comes in the class for half hour late. Luckily, I manage to reach just six minutes before she came in the class. My second individual assignment is submitted.

Video production and multimedia network is my interested field, even though I may not be expert in the field. But I didn’t get the knowledge of how to produce a video in the course I’m taking now. My friend told me, it is Media Technology student who learn how to produce a video. Why I don’t know about this before?

No point to sigh here. Anyway, I still surprise with the information conveyed by my lecturer today in the class. Actually, I’m not so interested in the confusing wire type. But I have no choice but to know them well. Haha…

Fine, what is RCA connector? According to Wikipedia (2009), it is defines as “a type of electrical connector that is commonly used in the audio/video market”. The name "RCA" derives from the Radio Corporation of America, which introduced the design by the early 1940s to allow mono phonograph players to be connected to amplifiers. An RCA connector is a plug and a jack designed for use with coaxial cable for frequencies ranging from the very lowest up to several megahertz. An RCA connector is sometimes known as a phono plug and jack.

The male RCA plug consists of a central pin measuring approximately two millimeters (mm) in diameter, and an outer shell whose inside diameter is approximately six mm. The plug shell is slotted rather than threaded, to facilitate quick insertion to, and removal from, the female jack or receptacle. Contact is maintained by physical pressure between the slotted shell of the plug and the smooth cylindrical barrel of the jack. The plug shell is connected to the outer conductor, or shield, of the coaxial cable, normally at electrical ground. The center pin of the plug is connected to the cable center conductor, which carries the signal. In the jack, the barrel is grounded and the center hole is plated inside to conduct the signal.

Regarding its function, RCA connectors are suitable for audio-frequency applications. They are also used in radio-frequency systems at low and medium frequencies, and at power levels up to approximately 100 watts. At higher frequencies or higher power levels, larger connectors are necessary. RCA connectors are designed for cables with small outside diameters (less than 6 or 7 mm) and are intended for indoor use only.

Connections are made by pushing the cable's plug into the female jack on the device. The signal-carrying pin protrudes from the plug, and often comes into contact with the socket before the grounded rings meet, resulting in loud hum or buzz if the audio components are powered while making connections. Continuous noise can occur if the plug partially falls out of the jack, breaking ground connection but not the signal. Some variants of the plug, especially cheaper versions, also give very poor grip and contact between the ground sheaths due to their lack of flexibility.

They are often color-coded, yellow for composite video, red for the right channel, and white or black for the left channel of stereo audio. This trio (or pair) of jacks can be found on the back of almost all audio and video equipment. At least one set is usually found on the front panel of modern TV sets, to facilitate connection of camcorders (through 3.5mm Jack to 3 RCA, also called Mini RCA plug), digital camera, and video gaming consoles. Although nearly all audio-visual connectors, including audio, composite and component video, and S/PDIF audio can use identical 75 Ω cables, sales of special-purpose cables for each use have proliferated. Varying cable quality means that a cheap line-level audio cable might not successfully transfer component video or digital audio signals due to impedance mismatch and poor shielding quality (causing signal-to-noise to be too low). Cables should meet the S/PDIF specification as defined by the international standard IEC 60958-3 for assured performance.