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Cell signal amplifier

Felinus

Sep 7, 2011
2
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Sep 7, 2011
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I've recently moved into a new apartment that has atrocious cell reception. I have looked online for low-powered cell repeaters, but being a college student on a college-student budget, I can't really afford a 100-200 dollar device that would probably only serve me for two years. So that got me thinking...why not build an amplifier/repeater? I can rather easily acquire necessary components from the engineering school on campus and I thought it'd be a nice project to take on before classes start. With my rather limited electronics knowledge, I'm guessing that such a device would require some antenna located outdoors (or anywhere indoors with a somewhat acceptable signal), a bidirectional amplifier powered by converted mains power, and then an indoors antenna.

Now, this is just all wishful thinking at this point, is there anyone with more in-depth knowledge about signal amplification and willing to help out a bit?
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
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Jan 21, 2010
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25,510
There are some people here more skilled than I in this particular field. I'm sure they'd tell you that there are some difficulties in building an amplifier that can switch very rapidly from transmit to receive and to do so without deafening itself.

When it comes to specific devices for mobile phones, I have seen a number of these devices, and as you've discovered they're not very cheap. This also is the case for devices coming out of China, so the cost of manufacture is obviously a significant component.

Added to that, there are likely to be licensing and other regulatory hurdles that you would be in breach of.

You *may* be able to take a passive approach. It is technically possible that pointing a high gain antenna at a cell tower, then linking this (via low loss coax -- remember the frequency) to a dipole mounted close to your phone will give you better reception.

If you can beg or borrow these things it may be possible to try it out in your environment before outlaying too much cash.

If your phone has an external antenna connection even better. Some car kits (with externally mounted antennae) for phones without external antenna connections work in a manner similar to this (so an in-car kit is another alternative)
 

Felinus

Sep 7, 2011
2
Joined
Sep 7, 2011
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2
Correct me if I'm wrong: the only difference between an active and a passive amplification setup would be the bidirectional amplifier. I would like to look into a passive setup due to its relative simplicity, but how strong of a signal would I be dealing with in the end? There's roughly 1000 sq ft that I'm trying to cover here, and I can access excellent reception once I step outside of the apartment.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
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25,510
A passive system will not work over an area as large as you want.

You would need an active system for what you want. Google "femtocell"
 

poor mystic

Apr 8, 2011
1,074
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Apr 8, 2011
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Use an extra-long earpiece/microphone feeder and operate the cellphone using a waldo. Then you can put the phone wherever you like...



How come there's no 'tongue in cheek' smiley on this site anyway :)
 
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