antenna gain

Hi,

In a previous post I asked how much range I would get from a pacific
wireless 12dbi omni-directional antenna that is vertically polarized
connected via a 20ft WBC400 cable rp-sma to n-male to my Netgear wg602.
Anyway it came today and I hooked it up and surprisingly found that my range
did not increase and according to netstumbler the new antenna is not any
stronger than my 2.2dbi dipole that came with the WAP. With the cable and
connector loss taken in consideration the antenna should still have a gain
of about 10dbi. Right now it looks like 3dbi. Is it that my WAP is not
powerful enough to supply the huge 48" omni or is the antenna defective. I
am really disappointed in the antenna as the whole kit cost me $120. If
anyone has a clue what is going on please reply.

Thanks for your help,
Nite Rider

Hi,
a 12 dBi omni will have a 3 dB beamwidth in azimuth of about 24 deg. so if
your antenna and the other antenna are off by more than 12 deg the signal
will drop off rapidly. that's about a 1:2.5 ratio ie 25' away from the
antenna the 3 dB points are +/- 10 ft on the centre height line of the
antenna

Also, does the wap have 2 antenna? , if so try swapping to the other
connector.

Also, you will not see the full gain of the antenna until you are at least
40' to 50 ' from the antenna

hope that is of some help

Greg


"Nite Rider" <(E-Mail Removed)> wrote in message
news:UuE1b.78675$(E-Mail Removed) t...
> Hi,
>
> In a previous post I asked how much range I would get from a pacific
> wireless 12dbi omni-directional antenna that is vertically polarized
> connected via a 20ft WBC400 cable rp-sma to n-male to my Netgear wg602.
> Anyway it came today and I hooked it up and surprisingly found that my
range
> did not increase and according to netstumbler the new antenna is not any
> stronger than my 2.2dbi dipole that came with the WAP. With the cable and
> connector loss taken in consideration the antenna should still have a gain
> of about 10dbi. Right now it looks like 3dbi. Is it that my WAP is not
> powerful enough to supply the huge 48" omni or is the antenna defective. I
> am really disappointed in the antenna as the whole kit cost me $120. If
> anyone has a clue what is going on please reply.
>
> Thanks for your help,
> Nite Rider
>
>

"Nite Rider" <(E-Mail Removed)> wrote in message
news:UuE1b.78675$(E-Mail Removed) t...
> Hi,
>
> In a previous post I asked how much range I would get from a pacific
> wireless 12dbi omni-directional antenna that is vertically polarized
> connected via a 20ft WBC400 cable rp-sma to n-male to my Netgear wg602.
> Anyway it came today and I hooked it up and surprisingly found that my
range
> did not increase and according to netstumbler the new antenna is not any
> stronger than my 2.2dbi dipole that came with the WAP. With the cable and
> connector loss taken in consideration the antenna should still have a gain
> of about 10dbi. Right now it looks like 3dbi. Is it that my WAP is not
> powerful enough to supply the huge 48" omni or is the antenna defective. I
> am really disappointed in the antenna as the whole kit cost me $120. If
> anyone has a clue what is going on please reply.
>
> Thanks for your help,
> Nite Rider
>
>

Bear in mind the 12 dBi omni has a much flatter radiation pattern than the
2.2 dBi dipole antennas and it doesn't actually add any power. If the
terrain is relatively flat, range should increase substantially. Have you
tried measuring the signal at various locations? Have you tried measuring
the signal at locations level with the antenna?

Don W.

> Anyway it came today and I hooked it up and surprisingly found that my range
> did not increase and according to netstumbler the new antenna is not any

Doesn't surprise me at all. Bear in mind that with that antenna you've
got about a 3 degree beamwidth. That's the problem we've been trying to
explain all along!

David.

> Also, does the wap have 2 antenna? , if so try swapping to the other
> connector.
>
> Also, you will not see the full gain of the antenna until you are at least
> 40' to 50 ' from the antenna

Wonder if Niterider has turned off the other antenna, otherwise it's
HIGHLY likely that given this new antenna pattern that the little WAP is
actually selecting the original antenna all the time anyway.

David.

The AP has only 1 antenna port.
"David Taylor" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> > Anyway it came today and I hooked it up and surprisingly found that my
range
> > did not increase and according to netstumbler the new antenna is not any
>
> Doesn't surprise me at all. Bear in mind that with that antenna you've
> got about a 3 degree beamwidth. That's the problem we've been trying to
> explain all along!
>
> David.

Hi again,
that should have been 24 deg in elevation, it's omni directional in az. I'm
sure you all knew what I meant

Cheers
Greg

"gcd" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Hi,
> a 12 dBi omni will have a 3 dB beamwidth in azimuth of about 24 deg. so
if
> your antenna and the other antenna are off by more than 12 deg the signal
> will drop off rapidly. that's about a 1:2.5 ratio ie 25' away from the
> antenna the 3 dB points are +/- 10 ft on the centre height line of the
> antenna
>
> Also, does the wap have 2 antenna? , if so try swapping to the other
> connector.
>
> Also, you will not see the full gain of the antenna until you are at least
> 40' to 50 ' from the antenna
>
> hope that is of some help
>
> Greg
>
>
> "Nite Rider" <(E-Mail Removed)> wrote in message
> news:UuE1b.78675$(E-Mail Removed) t...
> > Hi,
> >
> > In a previous post I asked how much range I would get from a pacific
> > wireless 12dbi omni-directional antenna that is vertically polarized
> > connected via a 20ft WBC400 cable rp-sma to n-male to my Netgear wg602.
> > Anyway it came today and I hooked it up and surprisingly found that my
> range
> > did not increase and according to netstumbler the new antenna is not any
> > stronger than my 2.2dbi dipole that came with the WAP. With the cable
and
> > connector loss taken in consideration the antenna should still have a
gain
> > of about 10dbi. Right now it looks like 3dbi. Is it that my WAP is not
> > powerful enough to supply the huge 48" omni or is the antenna defective.
I
> > am really disappointed in the antenna as the whole kit cost me $120. If
> > anyone has a clue what is going on please reply.
> >
> > Thanks for your help,
> > Nite Rider
> >
> >
>
>

"Nite Rider" <(E-Mail Removed)> wrote in message
news:BQZ1b.242476$uu5.50365@sccrnsc04...
> Ok I think I figured out the issue. Maybe I shouldn't start blaming the
> antenna so fast. I think the problem is my house as it is 50 some years
old.
> I did a little experiment. I placed the antenna where the signal would
have
> to go through the house's walls and signal went down by 80%. When I put
the
> antenna so the signal could go through the floor the signal was barely
> affected. My guess is that my walls are made up of something really bad
for
> radio waves, no wonder cell phone operation is bad too. I have decided
that
> in order to solve this issue I have to stick the antenna as high up on my
> house as I can so it would not go through walls but the floors.
Effectively
> maximising coverage. I'll tell you how it goes, I'll see if I have any
time
> tomorrow to mount the antenna.
>
> What do you people think? What type of walls do I have, I don't think they
> are metal?

Don't expect the omni to do a good job mounted overhead. The beam pattern is
all wrong. If you do mount it up there put it horrizontal. A low gain pannel
antenna would be better in this position (5dBi maybe, or the original omni
horizontal?). Check your roofing materials.

Your walls could be made of various materials. Anything with a metal mesh or
steel reinforcement would be bad. Plasterboard or insulation with a metal
foil backing would also be bad. A high moisture content could also kill the
radio signal. Beyond that any dense material will attenuate the signal.

Graham

In article <UZ%1b.2177$(E-Mail Removed)>,
GrahamH <(E-Mail Removed)> wrote:
>
>"Nite Rider" <(E-Mail Removed)> wrote in message
>news:BQZ1b.242476$uu5.50365@sccrnsc04...
(snip)
>> radio waves, no wonder cell phone operation is bad too. I have decided
>that
>> in order to solve this issue I have to stick the antenna as high up on my
>> house as I can so it would not go through walls but the floors.
(snip)
>Don't expect the omni to do a good job mounted overhead. The beam pattern is
>all wrong. If you do mount it up there put it horrizontal. A low gain pannel
>antenna would be better in this position (5dBi maybe, or the original omni
>horizontal?). Check your roofing materials.
(snip)

Would it also help to put a sheet of metal above the antenna so more
of the beam pattern is reflected down into the house? I've been
wondering if this really works, and if so then if a sheet of cooking
foil or a cookie sheet or whatever is good enough.

-- Mark

On Sun, 24 Aug 2003, Nite Rider wrote:
> Ok I think I figured out the issue. Maybe I shouldn't start blaming the
> antenna so fast. I think the problem is my house as it is 50 some years old.
> I did a little experiment. I placed the antenna where the signal would have
> to go through the house's walls and signal went down by 80%. When I put the
> antenna so the signal could go through the floor the signal was barely
> affected. My guess is that my walls are made up of something really bad for
> radio waves, no wonder cell phone operation is bad too. I have decided that
> in order to solve this issue I have to stick the antenna as high up on my
> house as I can so it would not go through walls but the floors. Effectively
> maximising coverage. I'll tell you how it goes, I'll see if I have any time
> tomorrow to mount the antenna.
>
> What do you people think? What type of walls do I have, I don't think they
> are metal?

Sometimes, the wire mesh in plaster walls is enough.

If you had a newer house, it could be the FOIL that surrounds the insulation.
that's stuffed into the walls (although, it's usually only in external walls
and the roof).