Wiring with no backbone

The average boat's coax cable TV backbone wiring at the best can be now be describe as venerable, and at the worst outmoded technology, yet it still persists. Your boat's coax cable backbone served its original purpose for decades well. It fed antenna and dockside analog cable system signals throughout the boat to all of those glass tube Panasonic TV's with VCR's built into them. But the world has changed. Analog cable TV systems in marinas are disappearing as cable system providers rapidly switch to digital systems requiring interface boxes.

Some new TV's no longer even have a coax connector. What would you use it for in this modern world? Digital audio, HDMI, USB, component video all yes. Jurassic era coax tech, not so much. Adding to this problem is many satellite TV receivers no longer have a coax cable "To TV" connection either. So what are the options? Let's take a look at the current technology.

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The AB switch is a common sight on many boats. It nearly met it's maker when TV stations moved to on air digital broadcasting making it just an "A" switch. Digital converters and TV receivers saved the day for this device, but it now hangs out in an assisted living facility eating stewed prunes.

The boats TV source signal leaves the AB box and is feed to a splitter. One cable goes in and many come out. In this case two, but larger splitters are common. The output from the splitter is connected to all of the TV's in the boat.

In the world of analog TV this worked very well. Each user could watch what they wanted. In the digital world this doesn't work very well. It works sort of in most cases with extra gear, but this comes with a price like lower resolution and signal loss.

The world has been changing, and the boat hasn't caught up yet, and to be honest it's been behind the technology curve for years. So the initial summary goes like this. Analog cable TV is rapidly disappearing and is being replaced with digital cable tech that isn't suitable for most boats. The bottom line is for all intents and purposes there is no longer a real need to include a shore cable TV connection for the boat. However digital on air TV is still very viable.

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There are many options both available and emerging to watch content. As mentioned digital on air TV is of very good quality (signal wise that is) and is widely available.

Satellite TV is also an excellent source with a huge array of programming. Emerging technologies allow streaming content off the internet directly, or saving the content on media servers or storage devices such as as flash drives. It's all good stuff, but sticking with the venerable coax cable backbone presents many challenges. It's worse than that, it's a pain in the ass to deal with. 

Here is a simple case in point. I'm installing on a newer boat a KVH TV1 satellite system with a DirecTV receiver. The receiver doesn't have a coax output I can use to connect to the boat's coax backbone. No worries, this is solvable if the TV's are smaller in size. I'll be back to this in a moment. The fix is to add a modulator that will convert a composite video output from the receiver and change it to a coax RF output. Since composite  video (the yellow plug) isn't exactly high resolution, the picture is marginal on larger sized TV's, but acceptable for smaller ones. So if this is an issue, why didn't I connect the TV's using component or HDMI cables so they get a better picture?

That's a good question, and the problem is both money, and boat construction. Most coax backbones are installed in a way that never contemplated either their removal or additions. Backbone installation usually occurs prior to cabinetry being installed. It can be very difficult and time consuming to pull new wiring to the location of each TV in a boat. Not impossible mind you, but on average a very expensive effort. Just to get the wiring to each TV, the TV itself must also be removed. A task that may odious in itself.

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What boat builders now need to be doing is installing a more flexible structured wiring system in their boats. This is done by home builders every day. They don't know exactly what the home owner will install, but they provide the wiring and infrastructure needed to support that anticipation.

A boat isn't any different. In the little sketch are the basics that should be in place. First is some location where all of the media gear will be located. This is where all of the wiring will home run to. In a house this is a closet. On a boat it could be a cabinet, or under a settee.

The location needs to be accessible, well ventilated and have easy power availability for both 12VDC and 110VAC. In my world accessibility is exactly like the word implies. You shouldn't have to take half the boat apart to get at it. 

Structured wiring is the second part of the equation. Today the minimum standard would be one RF coax feed (just for the very near future), and two HDMI cables. This would allow one HDMI cable to be used for primary content, and a second for DVD's or media servers. Primary TV locations such as the main salon should also have a fiber optic digital audio cable included for sound bars and surround sound systems.

Builders need to expect increasing use of USB ports on TV's. They are easy to get to when a TV is sitting on a stand in your home. Mine is one the back of the set. But if it's hung on the wall it becomes impossible to get to. If this is the case consider adding a USB extension cable to the back of the set to allow access. I use mine to do photo slide shows. I also have a Boxee to watch recorded movies and shows.

I know this will take some effort, forethought, and modest expense to accomplish, but failure to do this is at your customers long term expense. So now lets take a quick look at my KVH TV1 install if this approach was in place.

The KVH receiver gear, and satellite receiver now have a home. In the boat I'm installing it in I jammed the gear into a nearby cabinet with no power, and punched a series of holes to get the wiring in. I am concerned about the ventilation, we will see how well this works over time.

With the new approach I now no longer need the RF modulator, and associated AV cables. The HDMI cables would just plug into the receiver. The owner balked at the costs of pulling in a new HDMI cable to the master stateroom TV. With structured wiring in place a second receiver could be easily be added to the system and its HDMI cable would just jack into the back of it.

In the end, the largest single billing cost for my efforts is pulling wires from A to B. This is easily half or more of my average bill. There is an alternative boat builders could consider. It's this stuff called conduit that could be used to quickly get wires from one place to the other. I know it's new cutting edge technology, and many are concerned about the price they could pay for early adoption, but it's a new brave world out there. Think about it. I would rather have the structured wiring if I was a buyer, but at the bare minimum the conduit works also. Doing nothing is waiting to be culled from the herd.