cellphone antenna's

[zotdoc]

I live in a rural area with really poor cell phone coverage, ie, lots of blank areas just out of town, lots of dropped calls etc. Cellphone people keep promising another tower yada yada but after 6 years or so I'm tired of waiting. I've already wasted a few bucks on one of those paste on antenna's that you put directly on the phone and it did nothing. Do the so called passive repeaters that you stick on your vehicle window actually do anything or is that just another scam? Is their anything I can do to improove reception - the phone and it's components don't lend themselves to modifications.

[keymaker]

I recommend an old style bagphone
If you can still use them

Back in my day they were 5-10x more powerful<p>
And if that's not an option, upgrade your aerial.

[haklesup]

Those sticker antennas often cause the phone to go to full power even when the signal is strong thereby wasting power. Dispite the many testamonials by the makers, I have never seen a technical claim I could believe in. I also cannot believe in a "one size fits all" solution when it comes to RF signal manipulation given that most companies use different frequencies and modulation methods. Passive repeaters and thru car window antennas fall into the same category in my mind. Maybe they work for Analog mode.<p>Some cell phones do have an SMA connector for direct connection of an external antenna. This seems to me to be most likly to succeed. However, I tried this on my old phone once and could not see a difference.<p>Do you know anyone with another cell phone company. It may be that your carrier is behind and another one may perform better in your area. Some carriers share towers but others are incompatible. Ask around, you may be better off switching.<p>I'm not sure what a bagphone is but I would guess it was an Analog phone with a decent power output. Probably a battery hog too.<p>There are possibly cell models within your providers capability that may perform better than the model you own. Identifying what that model is will be a challenge though. Try asking in some of the cell phone related blogs. <p>There may be a trade off with battery life and reception. The phones with poor battery life may in fact be better recievers.

[Dean Huster]

Our Nokia has a little push-on connector on the back under a little rubber plug for an optional external antenna. In "fringe" areas, the external antenna gains anywhere from 2 to 5 extra "bars" on the signal strengh meter.<p>The problem with the "bag" phones, even if they were compatible with a current system, is that what you gain in greater power output, you lose in an older receiver design. The new teensy phones use lower power because they have receivers with several generations of better design with much greater sensitivity, lower noise and digital either-it's-there-or-it's-not reception.<p>I've never seen a phone with an SMA connector -- that's 'way to sophisticated and low SWR for a consumer product i.e., expensive, even for Motorola. The standard on the older phones was the TNC connector, a screw version of the BNC and about the same size.<p>Dean

[Bernius1]

Several points;
(disclaimer) FCC reg's don't permit modification of antennae. That said;
A) Does your phone have that external antenna plug? Sometimes a car cradle has power, speaker,AND antenna connectors. You then could put a 3dB or 5dB gain pigtail on your trunk, like the early Nextel/Motorola taxi systems.
B) Does the maker have a longer 'pull-up' style that you could pop-in?
C) As far as I can see, those foil 'boosters' only mirror the ground plane. They're either enlarging the ground plate area, or (more likely) making the RF field more polar. So you get 200% increase in 'radiated power' along the axis of radiation, but -200% at the 90-degree pole. And I agree with hacklesup about the max-power, though I thought the tower controlled power on the newer digi-systems.
FYI- the older trunked systems ran at 15W > 35W broadcast power (yes). I remember the 5dB antennae coming with a sticker saying 'keep 6+ feet away from antenna when Tx'ing'. But I think the phone company would have your head for overloading their tower on the cell freq's.
**Otherwise, drive around with a pocket full of quarters !!!! :-}

[haklesup]

It is my understanding that Digital phones use the lowest power setting to achieve acceptable transmission quality. This saves power for the battery but sometimes causes the phone to have borderline connections. It is as though the signal strength bars can also represent the inverse of the output power of the phone.<p>Once you are close enough to a tower, the phone is at minimum power and getting closer results in a better connection. When you move away from the tower and signal diminishes, the phone's output power is increased to compensate but only enough to satisfy the phone's preset gain level. Once you are too far, the phone switches to full power then to Analog and Full power for universal compatibility with the legacy cell system.<p>By that reasoning, If you are in the middle zone where power is variable, this is when a different model phone or service might make the biggest difference. The antenna stickers would also help here by forcing full power when it is not needed. If you are very rural, an external antenna might help more.<p>[ September 16, 2004: Message edited by: haklesup ]</p>