Whole-House Video Distribution & Cabling
View Cable, DSS, VCRs and Video Cameras From Any TV in Your Home By Changing TV Channels!
With the whole-house video distribution system shown here, every TV in your home will be able to view cable, antenna, or satellite channels as well as any video camera, VCR, and DVD player in the house, by simply changing channels.
The key to this system is a Dual RG6 Coaxial Cable system. Each room has a coaxial wall plate with 2 connectors. The top connector carries the output signal and is connected to the antenna/cable input of the TV. The bottom connector takes signals generated in that room from a VCR or video camera and feeds them back to an input on the distribution panel so that it becomes available to all other TVs in the house.
Note in the diagram how every room has the same twin coax connector wall plate. Having the connectors there makes it easy to add to the system later or move components around.
The modulator built into VCRs, cable boxes, and satellite dish receivers can usually only output on channel 3 or 4. Unfortunately, it's impossible to insert a signal from this type of device onto a cable or antenna line that already has channels. The channel 3 or 4 signal coming out of these units is 'wider' than it should be and the channel 3 or 4 signal will spill into nearby channels. The channel modulator inside your AV device lacks the expensive filtering of broadcast modulators, like those used at the cable company. Adding this signal to the coax will cause interference on channels 2 through 6. If want to distribute the audio and video from these devices, you are going to need an External Modulator.
In Room A, the VCR is connected to a modulator that outputs to channel 70 (for example). When the VCR is playing, any room in the house can view that VCR by simply switching to channel 70. In Room B, there are no TVs but there are two video cameras. The modulators take the video camera signals and modulate them onto channels 72 and 74 (for example). Again, any TV in the house can view what is on those video cameras by simply switching to channel 72 or 74. Room C only has a TV but it can watch any VCR or video camera in the house.
You can use freestanding modulators or use wall-mount modulators for a really clean custom look. Modulator like the pictured model have 'pass-through' connections so that AV cables come from your video device, into the modulator, then over to the television or home theater system.
When modulating a VCR/video signal onto a specific channel you need to select a range of channels that do not have any signals on them. If you cannot find any free channels you will have to use a Low Pass Filter to remove channels before inserting your signal. These filters will remove any existing channels above a certain point and allow your modulated channel to be placed on the cable without interference. It will also keep your modulated channels from leaving your home and being received by your neighbors. Without the low-pass filter, your signals could be radiated out the roof-top antenna or travel up the cable TV lines to other homes.
Note that most modulators, even the ones with left and right audio inputs, are not stereo modulators; the right and left channel separation will be lost once modulated. If you want to create true stereo channels choose a stereo modulator. Stereo MTS modulators also preserve any surround sound encoding in the signal.
To avoid the added cost of stereo modulators, one option is to send the stereo audio signals through your whole house audio distribution system if you have one. The equipment in the audio/video cabinet will usually include both your stereo VCR, DVD player, and satellite dish receiver as well as the amplifier/receiver that feeds the stereo speakers in the different rooms. Connect the audio outputs of the VCR DVD player, and satellite dish receiver to the appropriate inputs on the amplifier. Now when you want to watch TV in full stereo, all you have to do is turn on the amplifier feeding your room and switch it to the VCR or laser disc input source.
In homes where the cable runs from the main distribution panel are approximately the same length, you can use a relatively simple distribution panel which basically consists of an Amplifier and a Splitter.
Most likely, you will have runs of cable with vastly different lengths. Besides dealing with the inherent losses when splitting coax signals, losses will occur as the signal travels over the physical cable. Outputs to the longer runs will need more amplification than do shorter runs. Most commonly, people will add amplifiers ahead of the splitters to get more signal strength. This method invites two potential problems.
On shorter runs, many of the channels will be over amplified. You'll know when this happens if the TVs audio buzzes when white printing is superimposed on the screen, i.e. car leasing details or a newscaster's name. To fix this problem, install some Signal Strength Attenuator Pads on the coax line at the television to knock down the level of the signal. For the longer runs, you will find the lower channels may look good or be slightly over amplified, but the higher channels are noticeably weak. This happens because signal amplifiers will increase the signal strength of all the channels uniformly, but coax cable will attenuate the higher frequencies more than the lower ones. Install a Tilt Compensator to attenuate the lower channels while allowing the higher frequencies pass without any reduction in signal strength.
You can purchase Distribution Panels that have the short and long run inputs and outputs ready for connection. Panels like the pictured model are pre-engineered for cable runs of 100, 200, and/or 300 feet. These panels install in a central location and can be flush mounted between two wall studs or surface mounted. You can customized your own distribution system by building up your own distribution system with a selection of amplifiers, tilt compensators and splitter/combiners.
If you are building a new home make sure you have a twin coax cable system put in now since it is much more difficult to rewire later.