The basic purpose of a modulator is to take a scarp signal and convert it into a Rf signal that can be run through a traditional and coaxial cable and transfer it to the desired location. There are many different types of modulators such as 4 Channel Digital Modulator and Analog Modulator, these types of modulator are Continuous Wave Modulator, you also have Pulse Modulator.
What is Modulation?
Modulation is a process of combining two signals to produce a new signal with higher frequency, better quality, less noise and added data. This new signal generated now has two parts, One is called the Carrier signal which was the sinusoid signal and the other is called Data signal or Message signal. When the frequency of a signal drops, it is impossible to send it any further without loss of quality, so we have to increase the frequency which is called a frequency shift. All this is done by a Modulator.
Simple Digital Modulator
You typically have a satellite receiver and you want to send a signal at some distance to a Television via a RF cable. Most boxes don’t come with a modulator so that’s why you need an additional Digital Modulator. It is quite simple you might have a screen panel that displays the channel number and by channel number, you get the UHF spectrum that is divided from channel 21 to 69. So we can easily set the channels of different frequencies from channel 1, which comes in blocks of 8 Megahertz. We try to pick a channel that is not being used by another device in the system to avoid interference.
What you get on a Digital Modulator
You have simple on/off switch at the back of the modulator, with an RCA red and a yellow socket for audio and video input. You also have the option to put an alternative feed in through SCART. Then you have an antenna in and TV out socket, normally the antenna isn’t used but in a situation where you have to actually feed in a TV aerial with a certain number of channel and combine it in with the output from the satellite receiver and the modulator intertwines a channel with it and by feeding a signal cable back out that has the stereo channel with output from the satellite receiver.
How to connect the modulator
It’s quite easy to set up the modulator,you don’t need any additional help,you can do it by yourself in just 2 easy steps. The first thing you need to do is to connect the satellite receiver with your modulator through an RCA cable. Connect the yellow plug of the cable into the yellow socket of the Modulator for video and Red plug of the cable in the red socket for audio, attach the other end of the RCA cable in the receiver SCART. Now you have an output from the receiver that is going through the RCA cable into the modulator. The next thing you need is to supply power to your modulator and switch its power button on, Then you need a Coaxial standard cable with one female end and connect the modulator to the TV through this cable. Make sure you have plugged it in where it says TV out on the modulator.
The 4 channel Digital Modulator has many usages as it immunes the noise, it’s more efficient and if you have a high-frequency signal you can decrease the size of your antenna. In Digital modulator you can modulate using different techniques such as:
- Amplitude Shift Keying
- Frequency Shift Keying
- Phase Shift Keying
It depends on n the Modulator which of the technique it uses depending upon the type of signal being transferred.