An RF modulator or TV modulator is used in the video equipment, a television signal to modulate a radio frequency carrier frequency.
A practical application is, for example, the connection of home computers or video devices (eg DVD player) to older TVs without SCART socket via the antenna input. In general, the frequency range between 30 and channel 40 is used for it.
In older VCR, or satellite receivers, there were almost always simple modulators to receive the video signal in addition to the loop-through antenna signal at the antenna output of the device. Through the extinction of TVs without video input, this can be saved since the 2000s often. To connect a TV without composite connectors ( RCA or SCART socket ) with a video source newer design, an external RF modulator is inevitable. Also for supplying a video signal, for example, from a surveillance camera, the in-house distribution, a modulator is required.
Simple devices usually have an adjustment by screwdriver for a range of about 10 channels, better set the channel with fingertip control and PLL circuit and have an LED display for channel indication. You paint over the entire TV band. Nichtprofesionelle devices often produce interference in adjacent channels, so that the integration in an existing antenna or cable system is problematic. With professional equipment which is prevented by filter circuits.
- Video technology