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Old May 5th 04, 01:57 AM
coyotefred
 
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Default cell antenna options for remote area???

Hello!

I'm trying to improve the reception of my cellphone (LG LX5450) on the
alltel network in northwest Nebraska to a remote cabin. Within the
cabin itself I can only get weak analog reception with frequent call
drops. 'Hike up a nearby hill about 200 feet from the cabin, however,
and I can a very strong digital signal (the hillside faces the roof of
the cabin).

It may be that a decent yagi antenna, aimed properly and mounted on
the cabin roof, will be sufficient to get me a good signal. If not,
however, I'm looking for options. I could mount the yagi up on that
hillside, but the resulting coax run (200' or so) would, I imagine,
have me losing more signal than I gain.

I was intrigued by a couple of posts on this group as far as
reflectors, "passive repeaters," etc. I'm not exactly sure where my
signal is coming from up on that hillside, however...it could be east
or north. I guess a little experimentation/aiming with one of these
setups would be the key.

But if anyone has been in a similar situation to what I'm describing
here and discovered a decent solution, I'd sure appreciate hearing
from you.

Thank you for your time.
coyotefred
  #2   Report Post  
Old May 5th 04, 03:05 PM
JLB
 
Posts: n/a
Default

Contact Altel and ask them where is the nearest site to your cabin, and in
what direction.

There is also the chance that you can get to talk to a friendly person who
can give you suggestions as to an external antenna.

--
Jim
N8EE

to email directly, send to my call sign at arrl dot net
"coyotefred" wrote in message
om...
Hello!

I'm trying to improve the reception of my cellphone (LG LX5450) on the
alltel network in northwest Nebraska to a remote cabin. Within the
cabin itself I can only get weak analog reception with frequent call
drops. 'Hike up a nearby hill about 200 feet from the cabin, however,
and I can a very strong digital signal (the hillside faces the roof of
the cabin).

It may be that a decent yagi antenna, aimed properly and mounted on
the cabin roof, will be sufficient to get me a good signal. If not,
however, I'm looking for options. I could mount the yagi up on that
hillside, but the resulting coax run (200' or so) would, I imagine,
have me losing more signal than I gain.

I was intrigued by a couple of posts on this group as far as
reflectors, "passive repeaters," etc. I'm not exactly sure where my
signal is coming from up on that hillside, however...it could be east
or north. I guess a little experimentation/aiming with one of these
setups would be the key.

But if anyone has been in a similar situation to what I'm describing
here and discovered a decent solution, I'd sure appreciate hearing
from you.

Thank you for your time.
coyotefred




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Old May 6th 04, 01:06 AM
Scott Townley
 
Posts: n/a
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passive repeaters are a very specific application, that likely won't
work in your case.

Let's say you have a -70dBm signal at the hilltop (that's fairly
strong for either analog or digital). Even with two 10dB gain yagis
(one pointed at the cell site and the other pointed at your cabin),
the signal sent down (from the "passive repeater" is starting out at
-50dBm (-70+10+10, ignoring connecting cable loss). That's compared
to a power radiated of +50dBm at the cell site.
Anyhow, if the hill is 200' tall and 200' away, the space loss from
your "passive repeater" to your cabin is another 70dB or so, for a
final signal of -120dBm--too weak to be of any use.

On the other hand, 100' of cheap RG-58 loses about 14dB/100ft at
cellular, a 300' run would be -42dB, and if hooked to a yagi on a
hilltop gives you -70+10-42=-102dBm at the end of the cable...weak but
probably usable. Problem is, it would have to be connected directly
to the phone. Not very mobile at that point :-) The instant you hook
up an antenna (to reradiate) you will lose at least 10dB right off the
bat (the first foot of distance from an antenna at cellular is -22dB
space loss).

You could get lucky though...if the hilltop signal were -50dBm (that's
pretty damn strong) and you splurged on 15dB yagis, you'd end up with
-50+15+15-70=-90dBm which would work fine.






On 4 May 2004 17:57:01 -0700, (coyotefred)
wrote:

Hello!

I'm trying to improve the reception of my cellphone (LG LX5450) on the
alltel network in northwest Nebraska to a remote cabin. Within the
cabin itself I can only get weak analog reception with frequent call
drops. 'Hike up a nearby hill about 200 feet from the cabin, however,
and I can a very strong digital signal (the hillside faces the roof of
the cabin).

It may be that a decent yagi antenna, aimed properly and mounted on
the cabin roof, will be sufficient to get me a good signal. If not,
however, I'm looking for options. I could mount the yagi up on that
hillside, but the resulting coax run (200' or so) would, I imagine,
have me losing more signal than I gain.

I was intrigued by a couple of posts on this group as far as
reflectors, "passive repeaters," etc. I'm not exactly sure where my
signal is coming from up on that hillside, however...it could be east
or north. I guess a little experimentation/aiming with one of these
setups would be the key.

But if anyone has been in a similar situation to what I'm describing
here and discovered a decent solution, I'd sure appreciate hearing
from you.

Thank you for your time.
coyotefred


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Old May 6th 04, 04:24 AM
John Smith
 
Posts: n/a
Default

There are active Cell phone "repeaters" bricks, not sure what band though
(AMPS I'm sure of), and you would need power at either end.

"Scott Townley" wrote in message
...
passive repeaters are a very specific application, that likely won't
work in your case.

Let's say you have a -70dBm signal at the hilltop (that's fairly
strong for either analog or digital). Even with two 10dB gain yagis
(one pointed at the cell site and the other pointed at your cabin),
the signal sent down (from the "passive repeater" is starting out at
-50dBm (-70+10+10, ignoring connecting cable loss). That's compared
to a power radiated of +50dBm at the cell site.
Anyhow, if the hill is 200' tall and 200' away, the space loss from
your "passive repeater" to your cabin is another 70dB or so, for a
final signal of -120dBm--too weak to be of any use.

On the other hand, 100' of cheap RG-58 loses about 14dB/100ft at
cellular, a 300' run would be -42dB, and if hooked to a yagi on a
hilltop gives you -70+10-42=-102dBm at the end of the cable...weak but
probably usable. Problem is, it would have to be connected directly
to the phone. Not very mobile at that point :-) The instant you hook
up an antenna (to reradiate) you will lose at least 10dB right off the
bat (the first foot of distance from an antenna at cellular is -22dB
space loss).

You could get lucky though...if the hilltop signal were -50dBm (that's
pretty damn strong) and you splurged on 15dB yagis, you'd end up with
-50+15+15-70=-90dBm which would work fine.






On 4 May 2004 17:57:01 -0700, (coyotefred)
wrote:

Hello!

I'm trying to improve the reception of my cellphone (LG LX5450) on the
alltel network in northwest Nebraska to a remote cabin. Within the
cabin itself I can only get weak analog reception with frequent call
drops. 'Hike up a nearby hill about 200 feet from the cabin, however,
and I can a very strong digital signal (the hillside faces the roof of
the cabin).

It may be that a decent yagi antenna, aimed properly and mounted on
the cabin roof, will be sufficient to get me a good signal. If not,
however, I'm looking for options. I could mount the yagi up on that
hillside, but the resulting coax run (200' or so) would, I imagine,
have me losing more signal than I gain.

I was intrigued by a couple of posts on this group as far as
reflectors, "passive repeaters," etc. I'm not exactly sure where my
signal is coming from up on that hillside, however...it could be east
or north. I guess a little experimentation/aiming with one of these
setups would be the key.

But if anyone has been in a similar situation to what I'm describing
here and discovered a decent solution, I'd sure appreciate hearing
from you.

Thank you for your time.
coyotefred




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Old May 6th 04, 07:20 PM
coyotefred
 
Posts: n/a
Default

I see someone is selling some stronger yagis on eBay (40" (spec'd at
24dB) for $100 and 60" (36dB) for $130). Assuming those specs are
reasonable, from your math here it sounds like I might end up "OK"...

My other problem is connecting any external antenna to the LX5450.
Apparently the external antenna jack/port is so weak that people are
breaking their 5450s (the internal soldered connection to the on-board
stubby retractable antenna) when they try to plug in an adapter, that
no one is making any adapters for this phone. I don't know if a
"clip-on" adapter would work for something like this. It seems like
someone could craft something that would work here...

Someone had also suggested I look into one of those "signal boosters"
or "repeater amplifiers" sold by Wilson and others for $350-$500 (that
apparently boost your signal to the max 3watts). 'Kind of
expensive...and would the result be comparable to the external antenna
options we're discussing here?

(Scott Townley) wrote in message
On the other hand, 100' of cheap RG-58 loses about 14dB/100ft at
cellular, a 300' run would be -42dB, and if hooked to a yagi on a
hilltop gives you -70+10-42=-102dBm at the end of the cable...weak but
probably usable. Problem is, it would have to be connected directly
to the phone. Not very mobile at that point :-) The instant you hook
up an antenna (to reradiate) you will lose at least 10dB right off the
bat (the first foot of distance from an antenna at cellular is -22dB
space loss).

You could get lucky though...if the hilltop signal were -50dBm (that's
pretty damn strong) and you splurged on 15dB yagis, you'd end up with
-50+15+15-70=-90dBm which would work fine.



  #6   Report Post  
Old May 7th 04, 02:36 AM
Scott Townley
 
Posts: n/a
Default

Anyone selling a 60" yagi with 36dB at 800MHz is a liar :-) It can't
be done (5' tall panel antennas on top of the base stations are only
12dBi).

The "signal boosters" can work. But it still needs to go up top of
the hill; if there isn't enough signal at your cabin for the phone,
there isn't enough for the booster to start with. And then you'd need
power and weatherproofing up there.

The signal boosters work great for AMPS, but not necessarily for CDMA
(you mentioned Alltel so I am guessing that's their digital service in
NE). In fact I don't believe the FCC has type-accepted any CDMA
signal boosters for subscriber use.

On 6 May 2004 11:20:48 -0700, (coyotefred)
wrote:

I see someone is selling some stronger yagis on eBay (40" (spec'd at
24dB) for $100 and 60" (36dB) for $130). Assuming those specs are
reasonable, from your math here it sounds like I might end up "OK"...

My other problem is connecting any external antenna to the LX5450.
Apparently the external antenna jack/port is so weak that people are
breaking their 5450s (the internal soldered connection to the on-board
stubby retractable antenna) when they try to plug in an adapter, that
no one is making any adapters for this phone. I don't know if a
"clip-on" adapter would work for something like this. It seems like
someone could craft something that would work here...

Someone had also suggested I look into one of those "signal boosters"
or "repeater amplifiers" sold by Wilson and others for $350-$500 (that
apparently boost your signal to the max 3watts). 'Kind of
expensive...and would the result be comparable to the external antenna
options we're discussing here?

(Scott Townley) wrote in message
On the other hand, 100' of cheap RG-58 loses about 14dB/100ft at
cellular, a 300' run would be -42dB, and if hooked to a yagi on a
hilltop gives you -70+10-42=-102dBm at the end of the cable...weak but
probably usable. Problem is, it would have to be connected directly
to the phone. Not very mobile at that point :-) The instant you hook
up an antenna (to reradiate) you will lose at least 10dB right off the
bat (the first foot of distance from an antenna at cellular is -22dB
space loss).

You could get lucky though...if the hilltop signal were -50dBm (that's
pretty damn strong) and you splurged on 15dB yagis, you'd end up with
-50+15+15-70=-90dBm which would work fine.


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Old May 7th 04, 04:55 PM
coyotefred
 
Posts: n/a
Default

So what would the gain be with that 60" antenna? I see 20-24" or so
yagis being sold all over with gains of 12-14dB or so. But from what
you're saying maybe these figures aren't accurate either? I guess I'm
just wondering whether it is worth it to spend an extra $60 for the
60" yagi rather than the more "standard" 20-24" size... ?

(Scott Townley) wrote in message ...
Anyone selling a 60" yagi with 36dB at 800MHz is a liar :-) It can't
be done (5' tall panel antennas on top of the base stations are only
12dBi).

  #8   Report Post  
Old May 9th 04, 02:02 AM
Tom Ring
 
Posts: n/a
Default

A 60 inch antenna at 800 megs is about 4.07 wavelengths. Plugging that
into the boomlength to practical gain formula gives 14.2 dBd. A super
tweaked one might give .2 or .3 more, but the bandwidth would be worse.

tom
K0TAR

coyotefred wrote:
So what would the gain be with that 60" antenna? I see 20-24" or so
yagis being sold all over with gains of 12-14dB or so. But from what
you're saying maybe these figures aren't accurate either? I guess I'm
just wondering whether it is worth it to spend an extra $60 for the
60" yagi rather than the more "standard" 20-24" size... ?

(Scott Townley) wrote in message ...

Anyone selling a 60" yagi with 36dB at 800MHz is a liar :-) It can't
be done (5' tall panel antennas on top of the base stations are only
12dBi).


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Old May 6th 04, 04:43 AM
Crazy George
 
Posts: n/a
Default

Fred:

Make a corner reflector screen. Nothing fancy, for this frequency a couple
of square screens a foot or so in size. Put them together at right angles,
put the cell phone at a point which is a quarter wave from both surfaces
(dimension depends on band), and point the whole mess toward where the
signal might be coming from. Watching the "service available" light should
be informative for initial tests.

--
Crazy George
Remove N O and S P A M imbedded in return address


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