Spurious Transmitter Emissions   by Rata

Intentional RF interference is produced by AM and FM radio stations, as well as shortwave, CB transceivers, amateur transmitters, and any other communication device that transmits a Radio Frequency signal.

All these transmitters produce broadcast signals intended for reception by specific tuned receivers, but these intentional signals can also be received by other devices close to the transmitter or that are tuned in some manner to the transmitter???s frequency.

All transmitters also generate some signals outside their primary frequency. These signal transmissions are called spurious emissions. Like the transmitter???s primary frequency broadcast, they can be picked up not only by the intended receivers, but by any device near enough to the transmitter or that is tuned in some manner to one (or many) of the transmitter???s spurious emissions.

Spurious emissions can be harmonics (signals that are a multiple of the transmitter???s primary broadcast frequency) or mixing frequencies caused by the process used in most transmitters to generate the primary transmission frequency.

Mixing frequencies are usually close to the primary frequency or a harmonic frequency, but are not as strong as either of these. Finally, transmitters can produce noise??â