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Author Topic: Cell phone supplemental antennas  (Read 3347 times)

Offline JimBob

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Cell phone supplemental antennas
« on: 29/09/2007 04:15:59 »
I have poor reception where I live but a great plan - 1500 anytime minutes for less than $50 a month. I have seen advertised little thin "booster" antennas. Are they any good, has anyone had any experince with them

And to make this a scientific topic. "How do they work?"



 

another_someone

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Cell phone supplemental antennas
« Reply #1 on: 29/09/2007 04:35:49 »
My guess is that if they are passive devices they are unlikely to make much difference (excepting if you can move them to a more favourable location for reception). 

If they are active devices (i.e. RF amplifiers), then I can imagine they would boost the signal.

In theory, a larger antennae might be able to pick up more signal, but I would guess that the phones are tuned to the antennae they have, and any attempt to put a different antennae onto the device will detune it.
 

Offline techmind

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Cell phone supplemental antennas
« Reply #2 on: 02/10/2007 23:56:04 »
These "devices" usually work by a combination of wishful thinking and separating the gullible from their money!!!

You're better off taking your phone to the top floor of the building and leaving it somewhere not too close to your body or metal (which will block the signal or detune the antenna somewhat).

Bear in mind that to work the phone not only has to receive the signal from the network, it also has to make its own transmissions heard by the network. Realistically and practically the only thing which is likely to help (apart from going upstairs) is an external aerial. If you phone has an aerial socket (more commonly seen on older phones, sometimes behind a little rubber plug) you might try getting a car aerial kit and putting the aerial outside the house??? But that ties you to a wire... ;-)

Buildings absorb quite a bit of phone signals - is the reception noticeably better outside?
 

Offline Bored chemist

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Cell phone supplemental antennas
« Reply #3 on: 03/10/2007 20:15:46 »
It's certainly possible to use passive structures to improve the signal received (as in a sattelite dish). Whether or not these particular things work is another matter.
 

Offline techmind

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Cell phone supplemental antennas
« Reply #4 on: 04/10/2007 00:24:20 »
It's certainly possible to use passive structures to improve the signal received (as in a sattelite dish). Whether or not these particular things work is another matter.
Of course you could benefit from holding your phone at the focal point of a dish aerial directed toward the nearest base station... but owing to the wavelength of mobile phone signals (900MHz/1800MHz gives 33cm/16.5cm) you'd need a dish at least a metre or so in diameter to help much - which isn't too practical. You could also use a zoneplate structure of a similar size to do the same thing - again making it directional. If you had an external aerial socket then you could (in principle; there may be rules and regs prohibiting it) use a directional Yagi aerial (similar shape as a standard British TV aerial, but a correspondingly  smaller as the frequency is higher) - but again you've got to align it with the transmitter.

The bottom line is really that any passive device can ONLY help by making the transmission/reception more directional.
 

lyner

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Cell phone supplemental antennas
« Reply #5 on: 05/10/2007 23:25:12 »
Actually,  you could guide waves down  from the roof to a basement on a coax cable - possibly using a dipole at each end or even a high gain antenna on the roof.  The mobile phone would be held close to the lower dipole  in order to couple with the system; you wouldn't need to connect physically.
I have wanted to try this out but nowhere at home has bad enough reception, even at floor level. I just can't be bothered enough to make a screened box to test the effect on the mobile phone, though that would be the ideal way to do the experiment.
 

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Cell phone supplemental antennas
« Reply #5 on: 05/10/2007 23:25:12 »

 

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