Help: FTA dish installation with really long wiring

[ben99]

Hi,

I'm hoping to install an FTA dish at my home, and I'm wondering anyone can help me determine the installation feasibility.

I live in a town house. The existing cable wiring isn't entirely dish-friendly. My home is an end-unit of the building, and its length, I guess, is probably 80 to 100 feet long. Cable TV comes in from the other end of the building, where about 6 coax wires come out of the cable box and run length-wise across the building into separate rooms in my unit. From the cable utility box is the only place I have access to all the wires. The alternative, of course, is to run cable inside the house, which I prefer not to do.

I'm hoping the following strategy will work.

1. I'd like to bring the FTA dish cabling into the house from a window using a flat coax cable like the one Sadoun sells and connect it to one of the cable outlets in the house.

2. At the cable box, and once I uninstall cable, hopefully I'll have access to all the cable wiring into my unit. I'll connect the cable which the dish is connected to into a switch and connect it to all the rooms that I'll have receivers (2 or 3).

I haven't bought any equipment yet. Does anyone know what kind of effect the long wiring will have on signaling? We're talking about 200 ft. coax plus the 2 or 3-way switch. The switched output will also have to come back the whole length of the house. Anyone running a similar setup? Should I invest in the equipment and try this?

Also, do I need to get a special switch? Will a cheap Radio Shack 2x1 switch work? Also, do I need any special wires and connectors?

The real reason I'd like FTA is to receive from the Galaxy 13/Horizon 1 satellite, which I hear is really weak. I live in San Francisco area and I could get up to a 40 inch dish as allowed by the townhouse association. Will I have any problems with this? thanks.

Ben

 

[Mark_AR]

I've heard of 100 ft runs, but I think 200 is pushin it past any expectations of it working.

Cable is a lot different as the signals have amplifiers and distribution hubs. Whole different thing.

Your other questions I can't say. I have no experience with flat cable for FTA.

A 2x1 switch is for 2 LNB's and 1 receiver, not 1 LNB and 2 recievers. As far as I know anyway.

Bottom line - The 200 foot run is the killer. Your receiver has to provide voltage to the LNB (13 volts and 18 volts) to switch from H and V. With 200 foot run, in all likelyhood the voltage drop would cause the LNB not to switch or not function at all.

 

[ben99]

Are there any amplifiers I can put at 100ft? Will something like this work? I found it off Sadoun.

"In-Line Amplifier: Amplifies signal to compensate for splitters &
long runs, 12-20dB, 950-2400 MHz, Heavy-duty housing."

http://www.sadoun.com/Sat/Products/Accessories/PET10-6022.jpg

thanks

Ben

 

[oljim]

A inline amp will add to Voltage drop problem, not help

 

[ben99]

How do you calculate voltage drop in coaxial cable? The cable specification says it has a 75 ohm impedance but doesn't say anything about the length. Are they assuming that at short enough distances that it's negligible?

What does the voltage function look like? linear? polynomial?

thanks.

Ben

 

[ben99]

Could I summarize the problem as following?

1. There's a signal attenuation problem.
2. There's a voltage drop problem. (which is problem even worse if I want to install a motor there)

I think 1 could be solved with an in-line amplifier, right? If I'm correcting in understanding this, 2 is the killer. Is there a way the voltage from the receiver could be upped close to the dish? The only place I have physical access to the wires are at 0 ft, 100 ft and 200 ft. Is there a way I can inject more power into the wire at 200 ft, which is right by the dish, where I have access to all household power outlets? thanks.

Ben

 

[xrf1]

You can try the in-line amp, but I think probably you need an active amp. It has its own power source to supply itself and the LNB. Put it where nearest to the disk AND power outlet.

The in-line amp uses receiver power, therefore makes matter worse.

Flat coax is fine. Loss a little bit higher, but it's very short anyway.

The bigger dish the better, especially with weak sat. With 40" disk, you probably need pole mount.

 

[sksatellite]

A good coaxial cable can let you run up to 250 ft. without any problem. I did one installation couple years back for a middle east customer who live at a highrise building, the dish is set at top of the roof and I may have over 250 ft the cable run to customer's unit. The dish is on one side of the building, approximately ran 60 ft' of cable to the vent that the cable can go down to each floor's utility room, this is the 22 story building and customer is at fifth floor, customer's unit is 4 units down from the utility room across the hallway. He can get up to 75% on signal quality for T5 with a 30" dish.

 

[truckracer]

200 feet coax run

I have seen rg-6 quad shield ran 200 feet on a legacy dish 500 system.
It did actually work (believe it or not!) I could not tell you how much signal was probably lost with that many feet of cable.

The one thing we must remember is that coax cable of any type is not a very efficient means of transporting signals (aka: unbalanced transmission line)I learned this from my ham radio friends. It is however very good at shielding the contained signals from the nasty electromagnetic outside world, plus it is easy and non-discriminating to route.

Since free to air signals are typically pretty weak as compared to DBS signals (like D*tv and E* services) I think that 200 feet is too far at least with RG-6.
I have ran 200 + feet using RG-11 quad shield straight off the lnbf. This yielded satisafactory results. It has a #14 AWG center conductor and is very low loss as opposed to smaller gauge RG-6.

I would have to say you may encounter lnb voltage switching problems. It will somewhat depend on the lnbf and the receiver's ability to forgive low voltages on the line. You could be approaching the threshold of malfunction.

A word on inline amps. These little wonders do work in the right conditions.
But remember they amplify everything including unwanted signals that may be present on the line. They also add noise to the signal. Noise is the bitter enemy of any digital satellite system. This is the same criteria that seperates good lnbf's from cheap ones. How "quiet" the circuitry is will determine if the noise floor threshold is low enough for the receiver to make sense of the signal. also the amp will add to the volt drop on the already over-extended ailing line. Most inline amps use anywhere between 50 milliamps and 150 milliamps. If you try one use an active self powered amp.(make sure it has its own power supply from a wall outlet). Good luck, I think your system is worth a try. Trucker

 

[bigOleB]

I am using about 190' from dish to house with no problems. I use RG-6U Quad Shield to prevent any interference that could cause signal loss.

If the mods don't kill this link:
http://www.satelliteguys.us/showthread.php?t=46961

This should help. It helped me.

 

[Mr Tony]

I'm running 200' of RG6 with no signal issues