RadioBanter - question about cell phone boosters

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question about cell phone boosters

Do cell phone boosters really work, or is it just more hype to get you to
part with your dollars? In an area where there are hills and valleys,
sometimes I can't get a very good signal in the valleys. It seems like I get
calls all the time when I am in an area of poor reception. Has anyone had
any experience with these?

Joe

Cell phone boosters that I know about are all hype.

A cell phone is a low power radio, basically similar to one of the walkie
talkies that kids played with. Due to the limited power on Tx, I am amazed
they work as well as they do.

Still, they only work when you are more or less in line of sight of one of
the cell Tower antenna systems. Surrounded by hills, valleys, or tall
buildings, you are usually going to get poor reception.

The so called boosters tend to be flashy metal plates and such which claim
to focus the radio waves to get more range. Problem is even if they DID
focus the radio signals, which they don't, it would be a directional signal
and if you moved the phone away from the exact location, it would lose the
signal....

Jim
N6BIU

Just you try using one of those 3 transistor CB Radios from the '60's!

Power control is one of the technical achievements of GSM - the mobile
is instructed by the base to lower (or raise) its power appropriately.
Generally,
the maximum power from a handset is 33 dBm (at power level 5) which is
more than sufficient for the 35km wide maximum cell size.

The maximum cell size is determined by the length of the RACH burst.

"Jim Pennell" wrote in message
ink.net...
A cell phone is a low power radio, basically similar to one of the
walkie
talkies that kids played with. Due to the limited power on Tx, I am
amazed
they work as well as they do.

On Sat, 26 Jun 2004 23:04:01 GMT, "Jim Pennell"
wrote:

Cell phone boosters that I know about are all hype.

A cell phone is a low power radio, basically similar to one of the walkie
talkies that kids played with. Due to the limited power on Tx, I am amazed
they work as well as they do.

Still, they only work when you are more or less in line of sight of one of
the cell Tower antenna systems. Surrounded by hills, valleys, or tall
buildings, you are usually going to get poor reception.

The so called boosters tend to be flashy metal plates and such which claim
to focus the radio waves to get more range. Problem is even if they DID
focus the radio signals, which they don't, it would be a directional signal
and if you moved the phone away from the exact location, it would lose the
signal....

Are you saying these things are just basically passive horns like you
see used in microwave? "Booster" implies something a little more
*active*!
--

"What is now proved was once only imagin'd." - William Blake, 1793.

I think all that means "NO".

"Jim Pennell" wrote in message
ink.net...
Cell phone boosters that I know about are all hype.

A cell phone is a low power radio, basically similar to one of the
walkie
talkies that kids played with. Due to the limited power on Tx, I am
amazed
they work as well as they do.

Still, they only work when you are more or less in line of sight of one
of
the cell Tower antenna systems. Surrounded by hills, valleys, or tall
buildings, you are usually going to get poor reception.

The so called boosters tend to be flashy metal plates and such which
claim
to focus the radio waves to get more range. Problem is even if they DID
focus the radio signals, which they don't, it would be a directional
signal
and if you moved the phone away from the exact location, it would lose the
signal....

Jim
N6BIU

---
Outgoing mail is certified Virus Free.
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Version: 6.0.711 / Virus Database: 467 - Release Date: 25/06/2004

It is like having a four foot antenna !

Well, not really, this is just wrong.

Besides, your cell antenna is only inches long, having a four foot
antenna (equal to using a 'booster') will get you nothing
the cell frequencies are in the 900 Mhz and higher range.

roy

Jim wrote:

Cell phone boosters that I know about are all hype.

A cell phone is a low power radio, basically similar to one of the walkie
talkies that kids played with. Due to the limited power on Tx, I am amazed
they work as well as they do.

Still, they only work when you are more or less in line of sight of one of
the cell Tower antenna systems. Surrounded by hills, valleys, or tall
buildings, you are usually going to get poor reception.

The so called boosters tend to be flashy metal plates and such which claim
to focus the radio waves to get more range. Problem is even if they DID
focus the radio signals, which they don't, it would be a directional signal
and if you moved the phone away from the exact location, it would lose the
signal....

Jim
N6BIU

Oh, I agree that the power control is a major part of why cellphones work
as well as they do....

I was making a point that people need to consider cellphones as relatively
short range radios. There is a tenancy to expect cellphones to work all the
time, anywhere. But, most radio systems DON'T work that well.

-----------------

As for boosters, the ones I've seen ARE passive. An active booster
system would be fairly expensive. If they really worked, the cellphone
manufacturers would have them as an option and just about everbody would own
one.

Jim Pennell
N6BIU

Joe wrote:
Do cell phone boosters really work, or is it just more hype to get you to
part with your dollars? In an area where there are hills and valleys,
sometimes I can't get a very good signal in the valleys. It seems like I get
calls all the time when I am in an area of poor reception. Has anyone had
any experience with these?

Snake oil.

I suppose the idea is that the booster couples to the antenna, and
concentrates the phone's power along the horizon. That keeps you from
wasting power shot into outer space, making it more likely that power
will reach the base station. Same thing can happen in reverse: by
making the antenna more sensitive to signals arriving along the horizon
(where they come from) rather than those coming from outer space.
(where there are no base stationsgrin)

Problem is... that the design won't work.

The ones I've seen are designed to insert in front of the battery. This
location has a few problems:

- The battery, which is mostly metal, shields anything inserted in front
of it. Including the booster.

- Any metal in the phone (including the battery, and the original
antenna) affects the directivity of the booster - its ability to
concentrate power along the horizon. Since the booster is not directly
attached to the antenna, the metal in the phone also affects the
indirect coupling of the booster to the antenna.

Every phone is different. The size, the shape, how far the battery is
from the antenna, it's all different from phone to phone. This means
that a single booster design cannot possibly work with every phone.
There would have to be a specific design for your phone.

- In any case, the boosters I've seen don't match any valid antenna
design I'm aware of. (they really look a lot like the "laundry tickets"
we used to use in the dorms at the University of Wisconsin back in the
1970s!) (I wouldn't be too horribly surprised to learn they *are*
laundry tickets...)

It is certainly possible to build a cell phone booster. It would have
to be custom-designed for your phone. And most users would regard them
as impractically large and cumbersome. (probably not
eye-doctor-approved, they'd be a serious poking hazard!)
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com

Jim Pennell wrote:
Cell phone boosters that I know about are all hype.

A cell phone is a low power radio, basically similar to one of the walkie
talkies that kids played with. Due to the limited power on Tx, I am amazed
they work as well as they do.

Still, they only work when you are more or less in line of sight of one of
the cell Tower antenna systems. Surrounded by hills, valleys, or tall
buildings, you are usually going to get poor reception.

The so called boosters tend to be flashy metal plates and such which claim
to focus the radio waves to get more range. Problem is even if they DID
focus the radio signals, which they don't, it would be a directional signal
and if you moved the phone away from the exact location, it would lose the
signal....

Jim
N6BIU

They are as good as the $19.95 decals that were hyped on TV a year or so
ago. Those are now sold as a joke for $.25 and not worth that amoumt

Ted in Atlanta