31 January 2011

POWER - Which Watts are Which?

By Yorkville Audio
Images extracted from: http://affordableaudio.biz/

Amplifier power ratings these days tend to be in watts expressed as "continuous average" or "burst average" or "peak" or "music power" or "continuous music power", etc. In the old days, the nomenclature was "RMS" which stands for "root mean square" and reflects the results of a test for the amp's long-term, continuous output capability.

Other, more modern tests tend to net fairly similar results but are more complex and require more sophisticated equipment. Two ratings which are worth looking for are Continuous Average Power and Burst Average Power.

The first rating will be similar to what an RMS test would net and the second one will be higher, reflecting the amplifier's ability to repeatedly produce clean peaks which last for at least one complete wavelength.

26 January 2011

What is RF Power Meter?

You should be familiar with RF Meter if your job is to service transmitters. Each RF power Meters has it particular frequency and power range to measure specific transmitter. Conversely, it also has features such as plug in where you can adapt a different power and frequency range.  Basically, the RF power meter is specifically design for certain impedance level such as 30, 50 or 75 ohm and connected to the transmitter via coaxial cables.

You can connect the RF meter between the transmitter output and the antenna or dummy load (see fig below) or a power attenuator can be connected a head of the power RF power meter to reduce the power a level within the range of the RF power meter. Most RF power meters measure both forward and reflected power. If the impedance of the antenna or dummy load isn't equal to coaxial cable impedance, not all the power sent down the cable to the antenna will be radiated.

Some of this power will be reflected and travel back (along the coaxial cable) to the transmitter, where it is dissipated as heat in the transmitter circuits (mostly in the final power transistors). Therefore this can cause damage to the transmitter. This however can be avoided since the RF power meter can measure the reflected power from the antenna and immediate action be taken to avoid serious damage to the transmitter.   Some RF power meter have built in dummy load which is a plus since it eliminate the need for extra coaxial cable.

14 January 2011

One Simple Click Stress Free Audio Streaming

This is the absolute solution for online radio or better known as internet Radio. As Internet Radio technology improves, more and more commercial radio stations are able to broadcast through internet and be heard all over the world. 

Unfortunately, the process of putting the audio online is not as easy as it may sound. I have tried many methods of streaming and always have hiccups and the end result is usually not satisfactory. 

However this company named StreamOn is somehow or rather worth looking into. I have tried listening to their demo and it sound fantastic. 
StreamOn offers several different packages at the following sound qualities:
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    Stereo sound. Dial-up accessible, great for talk radio and AM radio stations.
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    Great Stereo Sound. Recommended for most stations.
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    CD quality sound. Recommended for high fidelity music stations.
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StreamOn streams are reliable, sound fantastic and play with one simple click.
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You have to listen to believe. Go ahead have a listen, read some testimonials, and discover the StreamOn advantage for yourself!