Despite the fact that it's been around for nearly a century, radio is still a pretty amazing thing. Radio waves, which are around us all the time, have fundamentally changed human society. Radio waves are behind the technologies of cell phones, GPS receivers, microwave ovens, and obviously radio itself. Despite this, a person can make a simple radio transmitter with just a 9-volt batter and a coin. But the transmitter is worth nothing without a receiver to demodulate the signal.
In order to send the signal, the transmitter needs first to modulate it. FM radio uses what's called "frequency modulation." The benefit of frequency modulation is that it is virtually immune to static. In technical terms, the transmitter's sine wave frequency changes only slightly based on the original signal. It's then the job of the receiver to decode this information.
FM radio transmits audio up to 100 kHz. However, since human beings can only hear up to 15 kHz, there is quite a bit of available bandwidth leftover. This is sometimes used for SCA transmissions, or subcarrier transmissions. These are additional modulated signals within the baseband audio. Many stations actually transmit on the subcarrier frequencies. To receive these signals, just like with regular FM broadcasts, you need a special receiver.
Radio SCA makes the most advanced SCA/SCMO/AM/FM radios available. We manufacture these radios to the specific and exact specifications, to ensure you get the best possible product. The quality of our products are guaranteed, so when you purchase from Radio SCA, you know you're getting the best radio money can buy.
Commercial Free Radio
SCA FM Receivers