Coax for internet, amateur, tv and scanning

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jdcts

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Hey guys, I'm not sure if this is the right spot for my question, forgive me if it isn't. I live on a farm with 30-60ft trees. As the trees have grown I'm finding myself needing a freestanding tower for my television and Internet. As much of a pain as that sounds I'd like to set up an fm tower for my farm fm radio and for scanning local trunked systems along with fm signals.

Info... The tower is 65 ft tall with the antenna on top for the fm radio. I'd like to mount my satellite dish 25 ft up on the tower with the internet dish just below it a few feet. The house would be 250 feet away from the tower. I am fairly new to the scanning world, currently I have a rs pro 651 and would like to get a trx2 for indoor use. I need 3 coax for the dish, one for the Internet and one for the fm radio/scanner. These 5 cables would all be trenches underground together in a 1 inch poly pipe running from the house to the antenna. I'd like a coax switch in the basement of the house for a quick switch between the trx-2 and farm fm.

I'm guessing that rg6 low loss will be fine for the tv satellite and that rg8 low loss for the scanner/fm radio. My QUESTION is, will I have problems with signal loss over this distance for my satellite tv and fm radio? Also will running all these cables together in the poly pipe cause any interference? And finally is there any suggestions on cable size, quality and type that would work better for any of my applications. If a shorter distance was possible I'd do it...this is the best I have to work with. Any help with this would be greatly appreciated. Thanks in advance.
 

mmckenna

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So, at minimum you are looking at 275 feet of cable for your satellite and internet dish, more for your radio and scanner.

That's a lot of cable. Issue is that all cable has loss, and that loss increases with length and frequency. Unless there are -really- strong signals in our area, you'll probably lose a lot just between the antenna and the house.

Which means you have to make some decisions.
Ideally, you want your coaxial cable as short as possible. That means either pick up your house and move it closer to the tower, or pick up the tower and move it closer to the house. I take it that mounting the antennas on your roof isn't an option?
If you can't move the radios and antennas closer together, you'll have to get creative:

If there is power available at the tower, you could try terminating the internet coax at the base and installing the modem there. Then run direct bury rated (yes, I know it's in conduit) category 5 or 6 cable between the modem and your home.

For the satellite dish, you'd really be better off mounting it on your house to keep the cable run shorter. If that is absolutely not a choice, you are going to need something bigger than RG-6. You can look at RG-11 or cable TV hard line.

For your FM broadcast radio, you could use the RG-11, but that still might have some issues. Consider adding an amplifier near the antenna to boost the signal going back to the house to overcome the coaxial cable losses.

If you are going to be doing any transmitting, you really should use a dedicated coaxial cable. RG-8 is going to lose a lot of your signal in the cable, and maybe enough to make it unusable. For runs that long, you really need to look at something like 7/8" heliax or better, and that's going to get really, really expensive. Other option is to put the radio at the base and use a tone remote to connect to the house. That'll let you control the radio over regular twisted pair phone line.

If you are going to run a conduit from the tower to the home, the labor is in the digging. Make the trench big enough to lay in at least one 1" conduit just for 110v ac power. Put in a bigger conduit for your coax. If you are going to try running the bigger cable TV hardline and/or the Heliax, you really should be looking into at least one 4" conduit and maybe two of them.
 

ko6jw_2

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OK, take a step back. You are worried about path losses from trees, but want to introduce losses from long runs of coax. Consider, if you must put everything on the tower, using wireless links to your house and install the radios on or near the tower and remotely control them via one or more links. Ubiquity makes a range of devices that would work well. Yes, you would need some expertise in creating remote controls, but you would save a fortune on the coax - not to mention eliminate losses in long coax runs.
 

jdcts

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Thanks for the reply...lots to think about. The one option that I do have is to put the Internet dish on the top of the house due to its direction. The satellite dish might be a different story though, before when I talked to my local installer and technician, he told me for the dish I would be fine up to 500 feet with rg6 for the tv dish... I've been reading from a few different sources that I might need a booster or bigger line, what am I compromising by going this distance with rg6? I don't doubt that it isn't big enough line but how do some get away with it?

As for the vhf fm radio antenna and coax, would I only need the heliax if I was going to transmit or what could I get away with for size if all I was going to do was rx with a trx2 scanner? Also where is a good place to get heliax, what is a decent price for the stuff per foot? I shouldn't have a problem trenching, I'll rent a trencher for a couple hours, will make a 4 inch wide trench no problem.

Thanks again for the help!
 

jdcts

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I agree, it's a lose lose. When I bought the place I didn't know the Internet and satellite tv were blocked by a solid row of evergreens. That being said I wouldn't have changed my decision haha. With the house being a single story the trees are still 35fft taller than the house. I did try the tv and internet for myself. I can get standard definition tv in the direction the dish has to face but absolutely no HD. I do want to do it right regardless of the price. Thanks for the help guys!
 

mmckenna

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Thanks for the reply...lots to think about. The one option that I do have is to put the Internet dish on the top of the house due to its direction. The satellite dish might be a different story though, before when I talked to my local installer and technician, he told me for the dish I would be fine up to 500 feet with rg6 for the tv dish... I've been reading from a few different sources that I might need a booster or bigger line, what am I compromising by going this distance with rg6? I don't doubt that it isn't big enough line but how do some get away with it?

You'll know when it doesn't work. The receiver sends power to the dish. If the cable is too long, the inherent resistance in the long cable will starve it for power.

Why it works for some and not others might have to do with individual component tolerances, different grades of RG-6, or some people that cannot measure correctly.

As for the vhf fm radio antenna and coax, would I only need the heliax if I was going to transmit or what could I get away with for size if all I was going to do was rx with a trx2 scanner? Also where is a good place to get heliax, what is a decent price for the stuff per foot? I shouldn't have a problem trenching, I'll rent a trencher for a couple hours, will make a 4 inch wide trench no problem.

Thanks again for the help!

If all you are going to do is receive, then you still need a good cable and add a preamplifier near the antenna. For 300+ feet of cable, you are going to have a lot of loss at VHF frequencies.
If you run 300 feet of LMR-600, you'll lose about 3dB of your signal. That's half of what you receive or half of what you transmit. That's not so bad on it's own if you have good coverage.


7/8" heliax will drop about 1.4dB, or a bit over 25%.

Really depends on how much loss you can have and still hear what you want to hear.
 

mmckenna

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Keep in mind that the trees are going to continue to grow. A 65 foot tower may work for a few years, but eventually you'll have to either cut down trees, raise your tower, or find a different approach.
 

Ubbe

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I have 150 feet to my dish and standard RG6 had to much voltage loss to be useful as the vertical/horisontal switching are done by altering the voltage between 13v and 18v and the voltage didn't go high enough to do the switching in the LNB. I bought the thickest RG6 I could find and it's now ok but I still have to select the "increased voltage" option in the sat receiver.

If you don't have any H/V switching by voltage in the LNB it's probably fine but might need an inline amplifier to boost the signal.

/Ubbe
 

prcguy

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Most RG6 has a copper plated steel center conductor which is fine for RF but not for DC current. The two large direct to home satellite companies in the US specify solid copper center conductor to make sure the voltage drop is acceptable up to about 200ft runs.

Trees will have very little effect on VHF, a little more on UHF and 800 will be impacted the most for scanner use. I would put an antenna up high on the house for scanner use and you can usually find a place that can see over trees for satellite TV. Depending on where you live the look angle for a DirecTV or Dish satellite antenna can range from 60deg up for the lower US to 20deg for the upper north east.

I have 150 feet to my dish and standard RG6 had to much voltage loss to be useful as the vertical/horisontal switching are done by altering the voltage between 13v and 18v and the voltage didn't go high enough to do the switching in the LNB. I bought the thickest RG6 I could find and it's now ok but I still have to select the "increased voltage" option in the sat receiver.

If you don't have any H/V switching by voltage in the LNB it's probably fine but might need an inline amplifier to boost the signal.

/Ubbe
 
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jdcts

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Thanks for the replies. I may have found a shorter way...not easier but shorter. Either I could do an above ground wire to the house or I could directional drill under the long car port to save myself about half the distance. I could also move the tower to a different location if I were to do this. By the sounds of it it's almost impossible to have a 300 ft run without significant loss and not break the bank. I've measured out 70 ft plus tower height of 65. Roughly 140-150 ft in total.

Would heliax cable still be necessary or could I get away with something easier to work with? Also in your opinion would rg6 be fine for the satellite. This is definitely the more difficult option but if I could find a way would this make it more manageable? Thanks for the help! Muchly appreciated
 

mmckenna

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Would heliax cable still be necessary or could I get away with something easier to work with?

Depends on how well you want it to work.
Ideally you'd do a loss budget. You'd look at the signal you were trying to receive, how strong the signal is, what your antenna gain is, what your coax losses are, how sensitive your receiver is, and that would tell you if it would work.
If this is for hobby listening only, then go with some good RG-6 and either deal with the losses or add a preamplifier.
If you are going to be transmitting, then you want to use something like LMR-600, 1/2" heliax, or better. Again, it all depends on how much signal loss your system can handle and still work.

Also in your opinion would rg6 be fine for the satellite. This is definitely the more difficult option but if I could find a way would this make it more manageable? Thanks for the help! Muchly appreciated

Probably, if like the others said, find the 100% copper center conductor RG-6. You could also look at RG-11, or one of the 75Ω variants of LMR-400.
 

krokus

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If the planned tower location is optimal for the tower, then consider putting the radios as close to the base of it as possible, and remote operate things.

Sent using Tapatalk
 

wyShack

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Another option for FM and the scanner would be what is sometimes called a 'passive repeater'. Put up a good antenna then run the coax to a High gain TV antenna and point the TV antenna at your house. While this would have quite a bit of loss,so would a coax run. This will not likely work for the satellite or Internet as the 'dish' in those cases also has part or all of the radio in it. Another issue you may run into is the length limit for network cable like Cat5 and 6 is only 100 meters (330 feet) at best.

Putting everything at the tower and remotely controlling everything over Wifi may be the most workable solution. When running power out to the tower remember voltage drop. I would stick with wifi to avoid issues with 'remote ground'- the difference between 'ground' at the tower and 'ground' at the house can be quite large during lightning conditions or even windy.

Good luck and plan ahead-questions are less expensive than equipment.
 

jdcts

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It looks like I'm going to be able to make the shorter run work. I found some old 5/8 heliax cable that will come with the tower. It has 2 breaks in about 70 feet. Not sure if it would be best just to go with new cable or have two joiners in the first 70 ft... If not I might try for just a straight run of either heliax or lmr. The tower has a large hinge to lower to the ground so it should be an easy set up! Looking forward to the project. Thanks for the help!
 

mmckenna

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Any used coaxial cable should be suspect of having issues.
Especially if it has breaks in it. Depending on the type of cable, it may have an air core, which can allow moisture to travel easily and allow corrosion to form at the low points. If it's a foam core, water can still travel.

As for 5/8" coax, make sure you figure out what it is. Standard Heliax will run 1/2", 7/8", 1 1/4", etc.

Also, adding connectors will increase loss, while minimal, it's something to consider.

I'd really recommend new coaxial cable if you can afford it.
 

lmrtek

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At 250 feet from the tower, you will need to use RG-11
and a line powered preamp to get your scanner signals and satellite signals to go that distance.
........
50 ohm coax is for transmitting and a total waste of money for your purpose.
......
Be sure to buy SOLID bare copper center conductor RG-11 so that it can power the preamp at the antenna.
......
 
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