Radio SCA makes SCA/SCMO/AM/FM radios to fit your needs. Whether you're buying for someone who is visually impaired (or you yourself are), you want to listen to multicultural programming, or enjoy any of the other SCA programming available, we have the products you need. We manufacture our radios to exacting standards.
SCA transmissions utilize the excess bandwidth available on FM broadcasts. Because FM transmissions don't use the full spectrum of frequency available to them, sometimes the leftover bandwidth is used for what are called subcarrier transmissions. Basically, this means that a completely different broadcast will sometimes be included in a different part of the wave spectrum than that of the primary broadcast.
FM stations are given 200 kHz in which to broadcast. So, for instance, if the station's frequency is 105.5 MHz, it is allowed to broadcast between 105.6 and 106.6 MHz. Stations never use the full 200 kHz available. In fact, they only need roughly a quarter of the frequency they are given. And since human beings can only hear up to a certain frequency (15 kHz, give or take), the transmitting frequencies will be limited, if for no other reason than this. Sometimes, though, stations will transmit a subcarrier transmission on the leftover bandwidth. These are the types of radios and receivers in which Radio SCA specializes.
There are times, however, when this additional broadcast will can bleed or cause interference on adjacent channels. This is caused by what are known as sidebands. In these cases, filters must be used to dampen this affect. Subcarriers above 75 kHz will be suppressed to a small percentage of modulation. This is done primarily to preserve the audio integrity of the surrounding frequencies.
Commercial Free Radio
SCA FM Receivers