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Video Distribution Tutorial (RF)

Article Details

Last Updated

24th o December, 2010

Video Distribution Tutorial

Your video distribution need may be as simple as getting a decent quality cable TV hookup to eachTV. Or you may be planning to have several video cameras that you want to view from any TV, andwant to "share" VCRs, satellite receivers, DVDs, etc. among all the TVs in the house.

In either case, if you're going to be wiring the video distribution system in your new or remodeledhome, you need to come up to speed on what it's all about and how its done. It isn't terribly difficultor complicated. In fact, I think its actually quite fun! Its pretty much a science until you get to the"tuning" part at the end.

So don't be scared. Dive in and enjoy! You can do a much better job than your electrician or local"cable guy."

A Little History(below) Introduction to Video Distribution(below)

o Glossary(below)

Section 2:Prewiring a Video Distribution System Section 3:Installing a Video Distribution System Section 4:Tuning and Troubleshooting a Video Distribution System

A Little History

Residential video distribution has come a long way since the days of a roof-mounted antennaconnected to a TV by a length of 300 ohm twin-lead flat-cable snaking through a window screen.Back in those days just about anybody could hook up a TV. And when a home had more than oneTV (which was rare) the other sets made do with rabbit ears!

Then came cable. At first the cable companies were more than happy to hook up your TVs for free,just to get your long-term business. If you had more than one TV, they just put a splitter on the sideof your home. They controlled the signal level coming down the cable so if they needed more signalstrength, they handled it "up at the pole."

After a while, the cable companies became the de-facto masters of video distribution and, thus,were able to charge for installations. Over the last few years, there has been a trend for thehomeowner to take charge of the low-voltage wiring within the home. This trend was driven, for themost part, by the phone and cable TV companies' attempt to make installations a "profit center."When phone and cable installations got expensive enough (and sloppily done, at that) thehomeowners started doing it themselves.

Today, it seems, neither the phone or cable companies care who does the installation. Which suitsus just fine, because we know that we can help you do awholelot better job than they would. All the
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cable company cares about (besides you paying your bill) is that you don't mess up the signal goingto neighboring "drops" (in other words--don't send any signals back up the cable) and that you don'tget them in trouble with the FCC by "leaking" their signals into the air.

Introduction To Video Distribution

Video distribution is all about getting a strong clear signal, of all channels (regardless of thesource), to all video destinations within the home. This involves three general functions: Gathering,and in some cases creating, the signals in one area; Combining, conditioning, and amplifying thesignals; And distributing the signals to their destinations.

The first thing your need to know about video distribution is that what you are really distributing isRadio Frequency (RF) signals. These signals, given the opportunity, would happily fly through theair to your TVs. But this method of video distribution is frowned upon by the FCC because theywould rather let the "licensed broadcasters" handle that method of distribution. Instead, we force theRF signal to go down shielded coaxial cables. Apart from the distribution task itself, the two most

important parts of creating a video distribution system are to keep your signals inside the cables,and to keep othersignals out of the cables!

A single coaxial cable can carry 130, or more, standard channel frequencies. Each channel includesvideo and audio components. With MTS encoding, each channel can even have stereo audio.

Contrary to an RF channel, which can coexist on a coaxial cable with many other channels,"baseband" video takes the whole cable, and doesn't even include sound! Baseband video and audiois what comes out of the RCA (a.k.a. "phono") jacks on the back of your VCR. Since it takes twocoaxial cables to transport a single baseband video and audio source, you generally want to convert

baseband into RF as "early" as possible. Which means as close to the source as possible.

You convert baseband to RF with a device called a modulator. Most modulators today are simplelittle digital boxes that are similar to,but the reverse of, a cable box. They have inputs for video andaudio, and an output for RF. (RF is almost always an "F" type connector.) You can use one or moremodulators to create your own "in-house" channels. In effect, you create your own cable TVcompany.

A cable coming in from your antenna or the cable company contains many RF channels and needsno modulation.

From a "block diagram" standpoint, there are four key pieces to any video distribution system: The

coaxial cables themselves, which serve as a conduit for the RF signals and allow interconnecting theother key pieces; RF Amplifiers that "boost" the RF signals to make up for the signal losses theother pieces impose; Combiners which "add" two or more cables together to create a single outputthat contains all channels frombothinput cables; And splitters that take a single input cable anddistribute the same signal to two or more output cables.

Planning a video distribution system is not difficult. You need to understand what the key piecesdo, have a blueprint of your home, and be able to do a little very simple math. That's it!

Ready to Go On?

This application note covers video distribution in four sections:
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The first section describes how to design (and spec out) a system. This section will help youdetermine what equipment to buy.

The second section covers prewiring the system. This section will tell you what to do whilethe walls are still open.

The third section details the installation of the system components. The fourth section describes how to "tune" and troubleshoot your system when you've got

everything hooked up.

Please note that this application noteis notabouthome theatersystems, although it obviouslydescribes how to get RF signals to and from the home theater system, and how to share hometheater video sources with the rest of the home. It does not, however, describe how to interconnect

baseband video/audio between the home theater components, or how to carry baseband or s-videosignals throughout your home. (A practice we do not recommend.)

Nor does this application note cover whole-house audio distribution. See ourWhole-House AudioTutorial. Although video source components may supply audio to the whole-house audio system,we will treat whole-house audio distribution as a separate system.

This document also does not cover DSS/Satellite signal distribution. See How Do I...ConnectMultiple DSS Receivers. To integrate DSS distribution with your video distribution system, designthe video distribution system first, then "piggyback" the DSS signals to the appropriate locations onthe video distribution cable as described in the DSS document.

Throughout this document you will see highlighted part numbers. These are hyperlinks to moreinformation elsewhere on our website about specific products. Unlikeother "sterile" documents that claim to educate you about whole-houseaudio without actually naming any products or even brands, thisdocument lets you click your way all the way through to actual productspecifications, pictures, and prices!

Video Distribution Tutorial -

Design

Section 1: Designing a Video Distribution System

This section of the tutorial describes how to design a video distribution system for your needs.

Dispelling a Few Misconceptions RF Video Distribution Concepts

o Integrity of RF Signals

o Splitters and Combiners

o Calculating RF Signal Loss and Gain

Counting INs and OUTs Choosing Drop Locations and Calculating Cable Lengths Designing the Headend

o With Discrete Components

o

With a Distribution Panel Choosing Modulators Section 1 Summary
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Misconceptions

Before beginning, I want to take a moment to dispell a couple of commonmisconceptions about video distribution. There are two kinds of things you can dowhen it comes to video distribution: The very easy and not-too-expensive; Andthe pretty hard and very expensive. In residential video distribution, we havealways stayed with the former. Here are some examples from the "pretty hard andvery expensive" category:

Combining Coaxial Cables With Common Channels I once said: I'll justcombine my in-house UHF channel 22 with the antenna feed. There doesn'tseemto be a channel 22 in my area. My channel 22 will surely drown out any little bitof any 22 than is coming in from the antenna. Silly me. It is astounding how littleof a signal it takes to screw up a perfectly good signal...when they are on the samefrequency. When you "combine" two coaxial cables containing RF signals, you

have to be absolutely sure the cables have no frequencies (channels) in common.Combiners are very simple little devices: Essentially they are transformers thatsimply "sum" the two input signals.

Removing a Channel Let's say that you wanted to remove a channel, or a groupof channels from a cable. Either just because you didn't want them in your house,or because you wanted to insert your own channels in their place. The cablecompanies do this with very precise, and obscenely expensive "notch filters." Wedon't do it in residential installations at all. The closest we come is with low-passfilters that remove all stations above a certain point. And they are not all that

precise: They begin "attenuating" stations at one channel, and as you go up the

channels get worse and worse, until you reach the rated cutoff, where the channelsare completely gone. This spread can encompass ten or more channels.

Adjacent Channel Modulation Let's say that your local area doesn't have achannel 3 being broadcast. Why can't you just take the RF output of your VCR,which is channel 3, and combine it with your antenna signal so that everyone canwatch the VCR? Well, you can...so long as nobody wants to watch channel 2 orchannel 4. Modulators (and the channel 3 output from the VCR is coming from alittle modulator built-in to the VCR) produce an RF signal that is much "wider" infrequency range than one channel. In order to keep this signal from interferingwith the adjacent channels you have to use an extremely precise (and expensive)

"narrow-band filter." The cable companies use the filters. In residentialapplications, we just make sure there is an unused channel above and below any"in-house" inserted channel.

If you keep these three limitations in mind, you won't "design yourself into acorner."

RF Video Distribution Concepts

Integrity of RF Signals

There are two parts to maintaining the integrity of RF signals; The first part is keeping yoursignals from leaking outof the cable. The second part is keeping outside signals from


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level coming in from the cable TV system or antenna. This ideal is called "unity gain." Byapplying a little math, and the table below, you can calculate the approximate losses andgains in your system to approach this goal.

RF signal levels are measured in dBmV which is a logarithmic scale of signal relative to onemillivolt. Since decibel values represent power levels, and are logarithmic, they can be

calculated with simple addition and subtraction. The main thing to remember about dB (forshort) values is that if the level drops below 0 dB (into the negative dB range), you areloosing actual signal information andno amount of amplification will beable to recover this lost information(picture quality.) In fact, amplifyinga signal that is below 0 dB willusually make the picture worse sincethe noise is now being amplified and

picked up. So you must insure thatyour signal levels never drop

dangerously near 0 dBanywhere in yourdistribution system. This iswhy the main RF amplifierus usually connected nearthe input side of thedistribution system; so thesignal is boosted early, andnever drops precariouslylow.

The only way to actuallymeasure the signal level iswith an RF signal levelmeter specifically designedfor this task. We ended up

buying one (they go for$1000 up) that we rent out to our local customers that are having trouble tuning up their verycomplex systems. But most folks get by just fine by just doing the calculations up front.

Cable TV companies are supposed to deliver around 15 dB of signal strength at the side ofthe house, but I've seen this range from below 0 to well over 25 dB. An antenna can deliver awide range of signal strengths depending on the strength and distance of the stations.

The optimum level at the wall-plate is between 8 and 15 dB.

Let's say that you want to take a cable TV signal to 8 TVs over up to 100feet of cable. An 8 way splitter has 12 dB loss, and 100 feet of RG6 has

around 4 dB loss. This total loss of 16 dB (12 + 4) must be offset by anamplifier before the splitter. An inexpensive15 dB amplifierjust fills the

bill. With such a setup, a 15 dB signal coming in will reach each TV with atleast 14 dB of signal strength. Close enough! And note that the signal neverdrops below zero. Working up a diagram such as this one, with the gainsand losses noted at each point, is an easy way to design a system.

Example 1 1-Input, 8 Output Design

Table 1 Rule-Of-Thumb Losses

Device Loss (-dBmV)

2-Way Splitter/Combiner 4.0




100 ft RG6 4.0

This table gives some rule-of-thumb losses for various splittersand cable lengths. Better quality splitters, such as the ChannelVision line, have slightly less loss than shown.
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This is an example of a more complex system design. It has one cable input, and three modulated signal inputs.(We assume the modulators put out around 25 dB.) These signals are combined, amplified, and distributed to12 destinations. Four of the destinations are longer 100 - 200 feet, and the rest are 100 feet or less. The mathshows that the signal strength, before the amplifier, is around 11 dB, and that there will be a 20 dB drop in thesplitters and coax runs. Since we want the signal at the TVs to be around 15 dB, we can do the math backwardsto see that we need around 25 dB of amplification.

Example 2 4-Input 12-Output Design

Counting INs and OUTsBefore you can get to the business of designing the headend, you need to know how many"in"s and "out"s you need. Cable TV coming in, or the Antenna feed coming in, counts asone (you can't use both simultaneously). Other inputs to the headend will come frommodulators generating in-house channels. Modulators are often remotely located (by theequipment they get their A/V signals from) and send their modulated signals to the headendover the "upstream" coaxial cable. Two or more modulators at the same location should betreated as one at the headend since their signals will be combined at the remote location.

Usually, all inputs at the headend are combined separately, then combined with the main

cable TV or antenna input. This is so the main input is not attenuated any more thannecessary before being amplified. Besides, you have more control over the level of the in-house signals than you do over the cable TV or antenna signals. Also, you can add additionalinputs later without greatly affecting the overall video distribution system design.

Outputs are the "downstream" cables that carry the signals to each of the wallplate "drops". Itdoesn't matter if there is actually a TV connected...the load on the system is the same.(Unused downstream drops should be capped with a terminator.)

If you end up with a lot more drops than you think you will ever have TVs, you can designyour headend to handle only a limited number of connections at one time, and switch cableswhen you move TVs. Most folks, however, design the headend to drive all the drops,whether used or not. Note: Although you should have as many upstream cables coming backto the headend as you have downstream cables, most of the upstream cables will not be
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connected at any given time. Only the upstream cables that are connected to modulatorsshould be combined into the system.

Now count the number of "in"s that you will have connected to the headend at any one time,and the number of "out"s you want to connect. These numbers will be used later to choose or

design the headend.

Choosing Drop Locations and Calculating Cable Lengths

Next you need to choose a location for your cable drops. Initially, we just use the cable droplocations noted on the electrical plans. Although these are usually placed by the architect, notthe owner, the count--if not the exact locations--are usually pretty close. The locations can berefined as the construction date nears. Approximations are fine at this stage. The main thingis to make sure you have cable drops in the rooms where you will need them!

In bedrooms, the cable drop locations are generally opposite the bed location. In the mainTV room, the location should be behind the TV/Home Theater. Don't forget to put a dropnear the computer in the study! TV on the PC is increasingly easy and popular, as are cablemodems. Also run some coax cable and some 4+ conductor telephone wire to the front doorlocation for a security camera. Along with security cameras come the need for a cable dropin the kitchen and other often occupied spaces, so that the owner can easily see through thecameras.

You need to determine a location for the headend. Basements and garages are OK. Althoughunder stairs and closets are a more common location. Attics are out due to excessive heat in

the summer. A "central" location is nice, but the vagaries of architecture often don't allowthis. Just make sure the location has access, through the walls, to all parts of the house.

One more "drop" will need to run to the cable entrance ("Point Of Demarcation") and/or theantenna location. If yours is new construction and you don't know where your cable will becoming in, check with other homes already built in the area to get a clue. If you haveunderground service, most often the entrance will be just inside the garage or on an outsidewall nearest the street. If you have overhead service, the entrance will be on an outside wallnearest the closest pole. The cable company will run coax and install a grounding block atthis point. You will connect to the other side of the grounding block.

Once the approximate locations are determined, you can estimate the cable lengths you'llneed. With your ruler, measure the distance from each drop to the headend, always turning atright angles. Multiply by the scale to get the number of feet, then add ten feet to each run toaccount for ups and downs at each end. Once you've done this for all drops, add the lengthstogether and add a 20% fudge factor. (Why the fudge factor? Experience. Trust me.) Thenmultiply by two to account for upstream and downstream runs. Is your number somewhere

between 500 and 1000 feet? Most of the time, it is. If less than 500 feet, you must have ahome with very few rooms. If over 1000 feet, you're building a pretty impressive place! One1000 foot spool of coax is the average purchase for our customers.

Designing the Headend
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Now that you've figured out how many ins and outs you have, where they go, and how farthey go, its time to think about the headend. There's two very different ways to go about this.The first is to choose a preconfigured video distribution panel that is appropriate for yourneeds. The second is to design your own video headend with what we call "video plumbing."This is where you screw a bunch of components to at piece of plywood on the wall andinterconnect them with short pieces of coax. While this is good clean fun, it isn't always the

prettiest, or the neatest solution. However, it may meet your needs much better than apreconfigured panel.

Designing the Headend with Discrete

Components

For designing a structure wire cabinet see

our (How do I wire a structured wire

panel?)in our knowlege base

When designing a headend with discretecomponents, start at each end and work towards themiddle, with the amplifier being the last componentselected.

Inputs

Bring in the cable TV or antenna feed into a two input combiner. Then combine the upstreamcables together in such a manner that the output of this combination is in the 12 - 19 dBrange. (Assume the output of modulators is 25 dB, most are this high or higher, and areadjustable.) Run this signal into the other input of the main combiner. You now have a single

cable with balanced blend of CATV/antennasignals and in-house signals in the 8 - 15 dB range.

Minimizing the drop on the main feed is a primaryconcern since you don't have much control over thestrength of this signal. If it happens to be veryweak, you don't want it to go below 0 dB in yourinput stage.

Outputs

Now see if you can group the "drop" (downstream)feeds into longer and shorter runs. Think innumbers like 2, 4, and 8 for the number of cables.And lengths like


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you will need two or more splitter stages(Example 4).

Unequal Outputs

If, however, you have some runs that arelonger and some that are shorter, you shouldsplit these up (2, 4, 8!) and design a systemwith some outputs stronger than others.Figuring a 4 dB loss per 100 feet of coax, a200 foot run should have 4 dB higher outputat the headend than the 100 foot runs.

Remember that the smaller the splitter, thestronger the output. Thus, use a single large

splitter to drive all the short runs, and one ormore smaller splitters to drive the longerruns. In an unequal-output system, you willalways end up with another level of splitterthat drives the final splitters.

Amplification

Now that you have the numbers for the total loss in your system, you can determine how bigof a main amplifier you need to counteract these losses.

Main Amplifier

Add up the total loss of your system byadding the loss in the input side to the loss inthe output side. For average systems, thisnumber is usually around 25 dB. Choose anamplifierthat has at least that much gain.Amplifiers with variable outputs are nicesince they let you easily adjust the gain tomeet your exact requirements.

The main amplifier will connect your inputstage to your output stage. (See Example 2.)

Isolation Amplifier

It is good practice to plan for an isolation amplifier onyour main antenna/cable input. This amplifier takesthe input antenna/cable signal and amplifies it a little,and the resulting output is then fed into the main

antenna/cable input to your distribution system.

The isolation amplifier serves two purposes: It may be

This is an example of a design with unequal outputs.Four of the outputs have 4 dB higher output than theother eight due to the difference in loss between a 4-way splitter and an 8-way splitter. The extra 4 dB willdrive a signal an extra 100 feet and end up with thesame level.

Example 5 Unequal Outputs
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needed if the input signal is very low, in order to boost it to a level that is roughly equal tothe other inputs so that it can be successfully combined in your input stage. And it keepsyour in-house modulated signals from going back up the cable or out of your antenna!

That having been said, in practice I usually find that an isolation amplifier is not needed: The

input signal is usually strong enough, and the attenuation between the two inputs of the maincombiner is quite high, so your in-house channels shouldn't "leak" back up the cable. Thereare always, however, exceptions. So at least keep in mind that you may ultimately need anisolation amplifier. (All the pre-configured panels include an isolation amplifier. Apparentlythe manufacturers believe it is important.)

Once you have the headend designed, you can put up a sheet of plywood and screw thecomponents to it, and interconnect the components just like your diagram!

Designing the Headend with a Distribution Panel

Thepre-configured distribution panel approach is much

easier and cleaner. Now that yourknow how many outputs youneed, just choose a panel withenough outputs. If the panel youchoose doesn't have enoughinputs, you can add an externalcombiner to get all your signals

in.

You can also mix a pre-configured panel with a custom design. For example, you could takeone of the outputs, amplify it, and split it eight ways to add a total of 7 outputs. Example 6

shows how you can turn one long run output into two short runs without even adding anamplifier!

Choosing Modulators

This example shows how you can ad an extra output to adistribution panel. You loose one long run output and gaintwo short run outputs.

Example 6 Adding an Extra Output
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Modulators are devices that take video and audio signals and turn them into an RF channel.Normally, modulators reside near the device that they are creating the channel for, such as a satellitereceiver. Although several cables are needed to connect the source to the modulator, a singlecoaxial cable can carry the audio and video signal to the headend. Exceptions to this include videocameras an other such sources where you might not want the modulator located out by the camera.In these cases, the modulator is usually placed at the headend and the camera's signal is carried in

its "baseband" form over coax to the headend.

The exact modulator(s) you choose is up to you. If you have two or more sources at a singlelocation, you can save some money by using a double- or triple-channel modulator.

The NetMedia modulators are smaller and a little less expensive than the Channel Vision line. TheChannel Vision modulators are easier to set up, come in more versions, and have a slightly strongeroutput than the NetMedia line. Our newer product line now includes the CELabs modulators thatare small, have channel displays like the Channel Visions. They also have the least expensive onechannel stereo modulator.On the high-end Channel Plus offers 3 & 4 channel stereo versions withS-Video inputs. All these modulators are digitally tuned, are drift-free, and perform equally well.

Video Distribution Tutorial - Install

Section 3: Installing a Video Distribution System

HomeTech Solutionsnewest update is currently part of our "how to install combo cable" which covers someof the installation for video distribution.Structured Wire TutorialInstalling Combination Cable

How Do I...Install Combo Cable

This application note describes how to install HomeTech's speedwrap or combination cable.

This application note only covers installations where the sheet-rock is not yet up. Installing combocable after the sheet rock is installed is a more complicated process.

What You'll Need

ToolsMaterialsMiscellaneous

Procedure

PreparationDo's and Don'tsDo It!

Related Links

Main Tools PageCombo Cable Page

What You'll Need

Tools
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A pair of wire cutters capable of handling the combination cable.GoodBetter A sharp pair of scissors for the fiberglass strands, if you have fiber. A helper. The spools weight over 70 pounds and the whole job goes much faster. A cable reel. You can improvise with a pole or rod and two chairs. A drill.

A 3/4" bitfor drilling the combo cable holes. A phillips screwdriver or screwdriver bit for screwing in mudrings.

Materials

The spools ofcombination cable. (Approx. one spool of 500 feet for every 8 runs.) A Single-gang (MP1S)or double-gang (MP2S)mud ring for each location. Miscellaneous cable hangers.(See below.) A box of #6 x 1/2" pan-head phillips sheet-metal screws. (For mud-rings.) A few cable-ties.

Miscellaneous

Marked up floor plan with each drop and the headend location noted.

For all headends except the FutureSmart Pro panels, you'll need the headend installcan.

Procedure

Do's and Don'ts

Do wait for the electrical and plumbing to be roughed in before installing low-voltagewiring.

Don't run combo cable within 18" of AC wiring for more than 18". Don't run combo cable and AC wiring though the same stud cavity (for more than 18"). Don't put a mud-ring on the same stud (even the other side) as an electrical box. Do cross AC wiring at a right angle. Don't kink or step on the combo cable. Don't bend the combo cable with a radius of less than 4".

Don't jerk the cable or pull at an angle to holes. (Doing so could tear the outer jacket andexpose the inner cables to damage. Do watch for sharp edges that could damage the cable. Don't use staples or other securing devices unless you are sure that they will not crush or

kink the cable. (Use our cable hangers, cable ties applied loosely with random spacing, orplastic stapleslargerthan the cable.)

Don't use securing devices inside stud cavities if it can be avoided. (This makes it easier toreplace the cable in the unlikely even it is damaged.)

Do label cables on each end. A marker and masking tapes works fine for temporary use. Don't try to splice or repair a cable. Instead, remove it, use the pieces somewhere else, and

pull a new cable.

Don't let the cable lay on the ground in the crawlspace or on the ceiling joists in a mainaccess area in the attic. Instead, support the cable from the roof or floor-joists with J-hooks.
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Do drill through center of stud. This spacing protects the cable from drywall screws. If youmust drill closer to one side, use a nail-plate on the face of the stud to protect the cable.

Do not drill through fire-walls, shear-walls, or specialized members like glue-laminateswithout first checking with the builder or local codes.

Do drill holes straight and even when passing cable through several studs at once...the cablewill pull much easier.

Preparation

Install the headend enclosure per the manufacturer's instructions. Place a combo cable spool on your cable reel immediately below the headend enclosure. Walk through the structure with your plans and a brightly colored crayon. Mark the studs

where the mud-rings will be placed, drawing an arrow to the right or left.

Do It!

Install the mud-rings. Use at least two screws, one on each face to hold the plate in place.Measure the height your other electrical boxes, from floor to center, for reference.

Starting from the headend, feed the cable through the top or bottom of the stud cavity of theheadend (no need to pass through the headend knock-outs at this point.) Pull the cablethrough each hole about 10 feet at a time. Keep working the cable through, 10 feet at a time,until you reach the mud-ring. You'll want about 18" of cablepastthe mud-ring.

Bend the center tabs back and secure the cableinside the stud cavitywith a tie-wrap. Double-check that the tie-wrap can be cut through the opening, the cable can be fished out, and thatthere will be at least 18" of slack cable available.

Pull back any remaining slack towards the headend. Cut the cable long enough at the headend so that the end reaches just past the furthest point

of the headend box. This will insure that the cable will be able to connect anywhere insidethe box. Fish the cable through the knockout in the headend can, secure it inside, and label it. Repeat for other runs.

Glossary

Baseband VideoAn unmodulated video signal. Depending on the regional standard, it may be NTSC, PAL,SECAM, etc. format. NTSC is used throughout north america. This signal does not carryany audio component and "takes up" the entire coaxial cable. Baseband video can betransported over the same kind of cable (I.E. 75 ohm RG-6 dual or quad shield coaxial) asRF video, but never at the same time. Runs of several hundred feet are possible withoutamplification, but amplification and distribution of baseband video is very different than RFvideo/audio and is not covered in this document. You can tell a baseband video input oroutput jack from an RF jack because the baseband jacks are usually non-threaded RCA style

connectors.CATV


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Short for Cable Access TeleVision. The method for distributing RF signals via coaxial cablerather than radiated through the air.

MATVShort for Multiple Access TeleVision. The method for distributing RF TV signals by

broadcasting them through the air.MTS Encoding

A method of encoding stereo audio along with the video signal on an RF channel. ManyTVs and VCRs can decode this stereo signal. Those that can't simply get the mono audiosignal.

RF Video/AudioOne or more video/audio signals modulated to Radio Frequencies. As in TV channels. Youcan tell an RF input or output jack from a baseband video or line level audio jack becausethe RF jacks are usually threaded "F" style connectors.

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