What Is The Best Fm Receiver?
Before FM radio was AM radio. The AM stands for "amplitude modulation" and refers to the method of encoding sound into the waves of electromagnetic radiation that a radio transmitter can produce. Sound is a wave and EM radiation is wave, so the first thought might be to simply use the sound source as the input to the transmitter. Unfortunately, the frequencies used by transmitters are in the MHz range (millions of cycles per second) while audible sound only reaches up to the KHz range (thousands of cycles per second). With this in mind, it's a simple step to decide that the sound can be encoded as changes in the amplitude of the EM radiation. Now we have a signal (the audio) and a carrier (the EM wave). So, we say that the carrier is modulated in amplitude by the signal - this is AM radio. This is a simple and workable scheme, but the environment has an effect on EM radiation that causes problems for AM radio. Buildings, hills, vehicles, atmospheric conditions and so on all attenuate EM radiation in some way. Because there is no way for the receiver (your radio) to distinguish the difference between environmental changes to amplitude (the attenuation) and the intentional modulation of the amplitude (the signal), the interference is heard as noise and distortion of the audio.
There are many schemes to limit this effect, such as multiband radio, but the most successful method of loading a carrier with analogue radio is frequency modulation - FM radio, invented in 1935 by Edwin Armstrong. In this scheme, the frequency of the carrier is altered based on the input signal. Because environmental factors are extremely unlikely to cause frequency changes in the carrier, even if they do cause attenuation, the signal remains undistorted over great distances and with many obstacles in the line-of-sight from the transmitter to the receiver That is, as long as the radio waves are not attenuated too far, the signal should be decoded from the carrier perfectly. What does this mean for choosing the best FM receiver? Well, the theory tells us that as far as the physics of radio go, any FM receiver is as good as the next. Of course, better quality components, amplification, speakers and so on, will drastically affect the final sound quality, but since there is little to distinguish in this respect between most electronics devices of a similar price point, what do we have left? Ultimately, it comes down to features. The best FM receiver and software, then, is the one that suits your needs. Decide what features you need (pause, rewind, recording schedule, schedule by program, save to disc, etc.) and then check the products from Hauppage (WinTV), Griffin Technology (the Shark) and so on, to see what suits you. All of the available PC based receivers will come with software, but it is worth also considering third party applications such as VCRadio or SnapTune that can provide a consistent interface across many hardware devices and offer a good level of basic functionality (VCRadio) or particular features (SnapTune). |
