Antenna towers

JeffA · EVDO Fledgling Joined: 12 Sep 2007 Posts: 15

I'm trying to figure out a cheap and dirty way of getting an antenna as high as possible without spending a ton of cash. I have an old telephone pole that I used for a TV antenna before Satellite, but It's at least 100ft from the house and I would need probably 150ft of antenna cable if I wanted to use it. From my understanding, that much cable would pretty much wipe out any gain from the antenna?

That being said, I'm looking at a way to mount an Antenna high in the air, but closer to the house. One thing I was thinking about using are threaded lead pipes. Keeping threading sections of pipe together and then cement the end into the ground. I could run the cable down the inside of the pipe. Any thoughts on this? Anyone have links to fairly inexpensive bracketed towers?

Thanks

JeffA · EVDO Fledgling Joined: 12 Sep 2007 Posts: 15

Oh.. I have an 80ft silo thats not being used but it's about 100 yards from the house. I was thinking this would make a great tower Smile

But how would I get the signal to the house without cable?

Would it be possible to mount the antenna on the silo, and then connect it to a wireless broadband router mounted just inside the silo (to protect it from rain). I would then use a point to point parabolic wifi dish to beam the signal from the router to the house where another parabolic dish is connected to a wifi card?

Sounds crazy but would it work?

n6gn · Posted: Wed Oct 17, 2007 9:06 am Post subject:

deparson · EVDO Junkie Joined: 30 Aug 2006 Posts: 248

If you have power to the silo then all you would need, I think, is a WiFi EVDO router, a wireless bridge at your house, then another WiFi router to provide signal to your house. 300' should not require any crazy antenna setup if it is LOS.

Be sure to install some way of remotely turning the power on/off to your setup when you need to reboot the remote hardware.

-D

JGZinv · Posted: Wed Oct 17, 2007 12:18 pm Post subject: reply

You may have an issue where if your router and card is out at the silo, whenever Sprint decides to do an update you'll have to run out there to get the card to go stick it in a PC. I've seen updates once a month before...

So I'd stick a small PC like a old laptop in a lockable outdoor enclosure, run the EVDO card and the antenna off that - run the laptop's ethernet to a wireless device/cable (note wireless will typically give you more lag if you play online games, and lag = bad).

Run some remote login software such as the free TightVNC on the laptop and a computer at home, then you can update or tweak the settings all you want from your house.

You should have "some" kind of enclosure out at the silo, rain might not get it (leaks?) but you will have humidity and moisture which could kill the components in the long run. Not to mention cold depending on where you're at. Also remember to ground devices properly, other wise you may have a very expensive lightning rod atop whichever structure you pick.

JeffA · EVDO Fledgling Joined: 12 Sep 2007 Posts: 15

Hyperlink tech sells powered external enclosures made specifically to house wireless routers. I'm guessing you can run an extension cord out to the box.

I'm still having a tough time deciding what I should to. I know my signal at the house is junk. I put my phone in DEBUG mode and I think I'm getting a reading of about -105db (1 bar) from the tower. The 3GStore has made some recommendations but I just dont think an amplifier with a wilson trucker antenna is going to do the job. I could be wrong since I have no clue about this EVDO stuff, but I don't want to order a bunch of stuff from the 3GStore and end up sending it back.

I'll post more after I get some reading this weekend.

I'm sure the Silo option will give me the best signal, but it seems like a pretty complicated endeavor. Nothings is ever easy Smile

xrayman · Posted: Fri Oct 26, 2007 10:26 am Post subject:

This is what I would try first. Get a Hyperlink Tech 2.4 GHz 24 dBi High Performance Die Cast Reflector Grid antenna along with the correct adapter / jumper cable to connect between the antenna and your EVDO card. Take the antenna and a laptop up to the top of the silo and do a site survey. If you have success than you can order more equipment to complete the installation. With the 30 days Sprint gives you before you are tied up with a two year contract you can to a lot of testing if you have the antenna and adapters on hand.

thebordella · EVDO User Joined: 12 Mar 2007 Posts: 26

Do what xrayman says. I did. I had a worse signal than you (-109 to -117) everywhere on my tree-enclosed property until I tried the grid antenna.

I have the grid antenna mounted about 28 feet in the air, but I cheated a little because my 20 feet of pole is planted on a second-story outdoor balcony, which itself is a good 8 feet above the ground.

For the 20 feet of pole, I bought two sections of 1 inch threaded steel pipe at Lowes, and just joined them by twisting them into a steel coupler widget doodag thiny. You could probably repeat the process to add a third section, but I might use a pipe wider than the 1 inch for stability. (Though it starts getting pretty heavy and needs to be secured pretty well.)

The 8 lb grid antenna is secured to the top of the pipe using the antenna's included u-bolt. You can tilt the antenna before locking it down although it's kind of a crapshoot to know how much you need to tilt it. (Or else you can cheat and tilt the pole.)

The thing with the grid antenna, and I can't stress this enough, is that it needs to be aimed very, very precisely. A matter of inches can spell the different between several db of signal or more. But if you can find the sweet spot, you can do a whole lot better than 105.

Of course, you still have to deal with a cable run. Try not to undermine your gains by using more cable than you need, and use LMR400 for the best value/loss characteristics. You might be better off shooting through trees or other obstacles just to have a short cable run, cmpared to a better line of sight but lots of cable. Worked for me -- shooting right through pine trees, tower 6.5 miles away, 1200kbps download speed. Right now I'm using 50 feet of cable but actually only need 12 feet, going to swap that next.

thebordella · EVDO User Joined: 12 Mar 2007 Posts: 26

Whoa -- edit!

I meant to say, I have *12* feet of pole, planted on a balcony 8 feet above the ground -- for a total of 20 feet in the air.

The steel pipes from Lowes are 6 feet each! Sorry. They did sell 10 foot poles, but there's no way they'd fit in my car, and would be heck to work with.

JeffA · EVDO Fledgling Joined: 12 Sep 2007 Posts: 15

Thanks for all the great info.

thebordella, are you using a Wilson Amp with your Grid Antenna?

thebordella · EVDO User Joined: 12 Mar 2007 Posts: 26

xrayman · Posted: Fri Oct 26, 2007 2:51 pm Post subject:

Besides testing at the silo as I suggested before do the test on top of your house also. You may be able to get a good usable signal using only a short mast as suggested by thebordella. That way you will only need 25 feet of LMR400 or LMR600 cable to connect to the EVDO card inside your house. At only 25 foot the loss difference is not much between the two cables. I always like to keep all the gain that I can. If you think you need an amp you can always add it later.
As for the mast I always use guy wires at the 10 foot level and above. BTW Rat Shack has 5 and 10 foot sections of 1-1/4" mast. It likely will cost and weighs less than 1 inch threaded steel water pipe.

onaquest · Posted: Fri Oct 26, 2007 6:51 pm Post subject:

xrayman · Posted: Fri Oct 26, 2007 11:29 pm Post subject:

If you google "mast guy wires" you will find a multitude of info.
An light duty antenna mast 10 feet in height from the mounting support point requires only one set of three guy wires, I like to use four wires if possible.
If you are using lag bolts or eyebolts to attach the wires to your roof you must find a solid framing member to screw into. Don't just depend on the thin sheeting material under the roofing to hold the screw threads.
Do not use silicon calk products to seal any penetrations you make in your roof. Most of the time they don't penetrate into the roofing materials to form a good water tight seal. Use a professional high quality product made for roof & flashing sealing.
When using ground anchors keep in mind the safety of people that may not see the guy wire. You may need to move the location or angle of the guy wire to prevent a hazard.
One thing people overlook is the twisting force wind has on the antenna and mast. You must attach the antenna to the mast using a very secure method. The mast will also need be secured at the base to prevent turning after you have the antenna pointed correctly.
Ground the mast to a 8 foot driven ground rod. Better to have a lightning bolt pass into the ground and not down into your house.
One last thing, watch out for high voltage electric lines! Many years ago in my youth I was helping a friend install a ham radio antenna. Long story short, before we had the guy wires attached a strong wind gust toppled it over onto the power lines in front of his house. No one got hurt but the antenna and mast was toast.

JeffA · EVDO Fledgling Joined: 12 Sep 2007 Posts: 15

Update:

This weekend I ran all over my property to see what kind of signal I could get with my cell phone. I put my nokia cell phone into DEBUG mode and used that to determine the strength coming from the tower I need. I know its not a perfect method, but better than nothing.

I ordered one of those 24dBi Hyperlink grid antennas.

From close to the top of that phone pole I was getting a signal of -92 to -96. To put the antenna up there would require about 125' cable run and the antenna would be difficult to fine tune point (especially in the virtical direction).

On the top of the hill in back of my house I was getting a signal as good as -86 (at about 5 feet above the ground). This is a good 200' from my home though. I figure if I was ever to try using this spot i would need to build some type of shack to mount the amplifier and router, and run PoE ethernet out here.

I did find a spot on my roof that I could get a -96 signal. I think its a sweet spot that has a small window. I've decided to give this spot a try. Antenna pointing and mounting should be easy, and I only need about a 50' piece of cable. I ordered a 50' piece of LMR400 with N/male connectors for $30 on ebay. Now I just need to call the 3G store today and order the AMP and Card. Will post my results with some pics.