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Author Topic: Home Cellphone Repeater  (Read 6549 times)
W8JI
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« Reply #15 on: September 07, 2012, 06:12:25 PM »

Quote
I can easily get the antennas far apart, since I have a 200 ft tower just 175 feet from the house. I could run 1-1/4  or 3 inch heliax from the tower antenna down to an antenna pointed into the house. I have piles of stuff, but no antennas.

How many neighbors do you have and how close are they? There has got to be a way for you to make money off of this. LOL

I wish I could make money. All I do is spend it.
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N4NYY
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« Reply #16 on: September 07, 2012, 07:06:19 PM »

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I wish I could make money. All I do is spend it.

The guy's farm that I buy my Christmas trees from, had a cell tower planted right on his farm. He is making a boatload of cash on a lease. If you neighbors need the cell service, maybe you can charge them!
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AJ4EV
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« Reply #17 on: September 08, 2012, 04:48:11 AM »

I have ordered the model 841263. I comes with a directional yagi and I should receive and have it installed in a few days. I'll post follow-up wth results.

73 de Terry
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W8JI
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« Reply #18 on: September 08, 2012, 07:23:43 PM »

I have ordered the model 841263. I comes with a directional yagi and I should receive and have it installed in a few days. I'll post follow-up wth results.

73 de Terry

Great, Terry!!

A buddy at mine at the FCC says these systems sometimes cause big problems if the oscillate. :-)

I thought my step-daughter had one, but it turns out she has one of the little VOIP things hooked into her cable internet.

I can get huge spacing here, so oscillation isn't a worry. Let me know how your system works.
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K6AER
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« Reply #19 on: September 08, 2012, 10:05:31 PM »

Tom,

Don't forget to put the amplifier close to the receiving antenna if possible. Coax loss just adds to the front end noise figure like any amplified system.

Mike
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W8JI
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« Reply #20 on: September 09, 2012, 02:13:59 PM »

Tom,

Don't forget to put the amplifier close to the receiving antenna if possible. Coax loss just adds to the front end noise figure like any amplified system.

Mike

Hi Mike,

That shouldn't be an issue. I can get line of sight to the cell tower about 6-7 miles away, well over any trees. My problem here is all the trees. If you google my qth and look at the path due east to Forsyth GA, it is all thick dense woods almost the entire distance.

I just have to get above the treetops, and the signal will be smoking strong!
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AJ4EV
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« Reply #21 on: September 12, 2012, 08:36:07 AM »

Outstanding Success! I received the system late yesterday and did a temporary install this morning. No more dead spots and no more missed calls. There are gain adjustments on each side of the amplifier to prevent oscillations that Tom spoke of. There is also the capability of installing more than one local antenna on the house side using splitters. I don't believe I will need those.

My QTH is 4.3 miles from the tower but is essentially blocked by the foilage. I'm looking forward to doing some spectrum analysis on the system when I have the time. The other good thing about the system is that it is engineered and manufactured in the good ole USA!

73 de Terry
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W0BTU
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« Reply #22 on: September 12, 2012, 11:03:12 AM »

Are highly directional antennas avaiable? I was even wondering if a high gain antenna well up over the trees coupled to another antenna pointed down at the house would do anything at all as a passive system.

Somewhere, I read about some people in a deep valley (and so no cell phone access down there) who simply put the lower antenna (which was omnidirectional) in their house. The other antenna was on a tower. The two antennas were simply connected with coax, no amplifier. Supposedly, it worked great. That's all I remember.
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N4NOO
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« Reply #23 on: September 12, 2012, 03:24:06 PM »

At one of the TV station that I worked at we had a Studio to Transmitter microwave system that at one point, on a mountain top, had a 300' tower that simply had two antennas back to back with a short amount of feed line between them.  It works great and still does 15 years later.  Try one pointed at the cell tower and one pointed at your house.  Cheep but effective.

Good luck,

Rick - N4NOO
« Last Edit: September 12, 2012, 03:28:03 PM by N4NOO » Logged
W8JI
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« Reply #24 on: September 13, 2012, 02:40:06 PM »

At one of the TV station that I worked at we had a Studio to Transmitter microwave system that at one point, on a mountain top, had a 300' tower that simply had two antennas back to back with a short amount of feed line between them.  It works great and still does 15 years later.  Try one pointed at the cell tower and one pointed at your house.  Cheep but effective.

Good luck,

Rick - N4NOO

I think I will try that.

I'll buy two good cell antennas, and mount one at 100 feet pointed at the Forsyth GA tower. I'll just mount another right next to it pointed down at the house about 200 feet away. If it doesn't work, I'll buy an amplifier system and move one antenna.
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WB6BYU
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« Reply #25 on: September 13, 2012, 03:40:04 PM »

I ran the calculations for such a system once, and to get a signal across a 10'
road on 2m required 3 beams, each with 10dB gain (don't remember if it was
dBi or dBd.)  That was to end up with the same signal at the receiver as
would have been received at the original antenna with a dipole.

While the numbers might not be exact, they did point out the value
of using the highest available gain for the fixed antennas, though this is
less important when there is plenty of signal strength to start with.

I also make up a pair of corner reflectors connected by a couple feet of twinlead
for my sister-in-law, who lives in a canyon, to be placed 200' up on the rim. 
These would have advantage of covering multiple cell bands, with the idea of
replacing them with a more permanent system once we verified preliminary
performance.  But nobody has bothered hiking up to the rim to install them,
so I can't report any results.


Before buying any antennas, however, check with your provider to see what
frequency band(s) they are using:  there are a number of them between 800MHz
and 2 GHz or so.
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W8JI
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« Reply #26 on: September 14, 2012, 05:50:26 PM »

I can measure the signal, and I have. It was up in the 800 MHz range. I'll do an exact look.

I ran some path loss numbers on the idea, and it does not look all that good unless I have some really large antennas or use an amplifier with normal size antennas. Unless I can find a large cheap surplus antenna with 15-20 dBd gain, it is starting to look like it will be a normal size Yagi antenna on my TV tower into a bidirectional amp, and then another beam pointed into the house.
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WB6BYU
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« Reply #27 on: September 14, 2012, 07:44:06 PM »

And how does it look if you run low-loss coax down the tower to a point much closer
to the house?
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W8JI
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« Reply #28 on: September 15, 2012, 05:04:41 AM »

And how does it look if you run low-loss coax down the tower to a point much closer
to the house?

I never looked at that. I do have some large cables, even stuff around 3", but I'd rather buy a bidirectional amp and use smaller cables.

I can use a 50 ft TV tower, which puts a lot of trees between the cell site and the antenna, or I can use a 200 ft tower about 150 feet away. That tower has a cable bridge of Rohn 20 and 25G mixed that comes within 100 feet of my house radio room area.  I was thinking of the house antenna on the house end of that bridge.

The cable bridge is not visable in this pix, but the support posts are. It is the closest tower to the camera.


http://www.w8ji.com/images/towers/Rohn%2065G/Web%20ready%20tower%20pix/220%20full+rot+300.JPG
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N4CR
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« Reply #29 on: September 16, 2012, 10:00:19 AM »

I can measure the signal, and I have. It was up in the 800 MHz range. I'll do an exact look.

I ran some path loss numbers on the idea, and it does not look all that good unless I have some really large antennas or use an amplifier with normal size antennas. Unless I can find a large cheap surplus antenna with 15-20 dBd gain, it is starting to look like it will be a normal size Yagi antenna on my TV tower into a bidirectional amp, and then another beam pointed into the house.

It seems to me that anything above passive would be prone to feedback. No?
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73 de N4CR, Phil

We are Coulomb of Borg. Resistance is futile. Voltage, on the other hand, has potential.
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