A channel modulator is the device that puts information (video and audio) on a specific frequency (channel) in your private cable system. There are a few different types of modulators that we use. You may need to locate a modulator in a head end rack at some point in time, so these pictures will help you find them. This specific modulator is a Drake VM600 Mini modulator.
On the front of this channel modulator you will see the power LED. The LED will be lit if the modulator is powered on. The channel that this modulator is used for is labeled, as you can see in the picture this channel modulator would be used for channel 20.
The four things that look like screws are actually where you can change the level settings of the aspect labeled next to them. Note: Audio and Video levels can be tuned by the user, but it is highly recommended not to touch the A/V and RF settings. You should only touch the A/V and RF settings if advised to do so by a SeniorTV Cable Technician. If adjustments are going to be made to the A/V and RF settings, a signal meter is highly recommended.
For instance, if the sound is too soft on a certain channel, you could turn the audio level up a bit. The audio levels should be balanced so that as someone flips through the channels on their television, they should not have to adjust the volume on their TV set. In a balanced cable system, all of the channels will be roughly the same volume.
If your video adjustment is too high, you will see tearing/buzzing around white colors. If you video adjustment is too low, you might see darker pictures that have an orange tint.
On the back of the mini modulator, there are the two input ports and the RF output port. The video input and audio input ports connect to your DirecTV receiver.
Below the audio input port, the power supply connects to the mini modulator. The RF out port is what connects this modulator to your private cable system.