I think true 16dbi OMNI antennas are rare if not non-existant. Antennas increase gain by increasing directionality. _________________ SIG:
I'm trying to teach you to fish, not give you a fish. If you just want a fish, wait for a fisherman who hands them out. I'm more of a fishing instructor.
LOM: "If you show that you have not bothered to read the forum announcements or to follow the advices in them then the level of help available for you will drop substantially, also known as Murrkf's law.."
Exactly... _________________ SIG:
I'm trying to teach you to fish, not give you a fish. If you just want a fish, wait for a fisherman who hands them out. I'm more of a fishing instructor.
LOM: "If you show that you have not bothered to read the forum announcements or to follow the advices in them then the level of help available for you will drop substantially, also known as Murrkf's law.."
Gain: 16dbi
Connector: SMA male with pin female connector
Frequency: 2.4G
VSWR: <1.5:1
Impedance: 50Ω
Power: 50W
Ambient temperature: -40~80?
Weight: 180g
Cable length: 3M
1 have 10 of these "on different Routers" and thay are AWSOME!
with the wrt300n v1.0 i can pickup my wifi for over a MILE and still able to stream a movie off my server.
Posted: Mon Jul 20, 2009 20:38 Post subject: antenna gain
An omni-directional antenna can still have gain, and yes that gain is achieved by changing it's original gain pattern. In this case, some gain from the higher elevation angles is "directed" more towards another direction, usually towards the horizon. The gain pattern is still circular, but is has a higher gain the an "isotropic (sp?) antenna. A colinear antenna is a practical example of this type of omni-directional antenna.
You might do a google search on colinear antennae to find out how this works.
Regards,
Bob
Joined: 22 Jun 2008 Posts: 2440 Location: Am now Dark_Shadow
Posted: Mon Jul 20, 2009 20:39 Post subject:
Exactly what i was talking about, thanks radioman. and thanks Murrkf for urging me to be cautions although I still don't understand what your talking about with the pole antenna making it directional. _________________ The New Me
Joined: 22 Jun 2008 Posts: 2440 Location: Am now Dark_Shadow
Posted: Mon Jul 20, 2009 20:41 Post subject: Re: antenna gain
robert-e wrote:
An omni-directional antenna can still have gain, and yes that gain is achieved by changing it's original gain pattern. In this case, some gain from the higher elevation angles is "directed" more towards another direction, usually towards the horizon. The gain pattern is still circular, but is has a higher gain the an "isotropic (sp?) antenna. A colinear antenna is a practical example of this type of omni-directional antenna.
You might do a google search on colinear antennae to find out how this works.
Regards,
Bob
and alot of pepole dont see or know the "Ground-Plane" Under and arround the antenna will Change the radiation angle pattern of your antenna even if its a Directional "beam" yagi or parabolic antenna.
Onmi antennas are more affected by its Ground-Plane orientation.
thats why us old ham radio operators and Hard core CBers would lay chicken wire down in a grid 4 to 6 inches under the ground all arround the tower for the beam. "about 60 to 120 foot circular pattern" Grounded to the house Cold water pipes and drounded to the tower
that improves the "DX" long distance Signals ALOT!
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My point is simply that many antenna manufacturers/sellers lie about the real gain. It is not that gain is impossible with omni but 16dbi is a LOT. 2 to the 4th power increase =16 times the range.
That means about 5km of coverage in every direction. So...just because it says it is, doesn't make it so.
There are genuine higher performance omnis available...this thread does discuss them...but they are not the cheap antennas you get on ebay for 20 dollars.
So, higher performance omnis....certainly. 16dbi might be unrealistic. I would be suspect of that claim....but I could be wrong too. _________________ SIG:
I'm trying to teach you to fish, not give you a fish. If you just want a fish, wait for a fisherman who hands them out. I'm more of a fishing instructor.
LOM: "If you show that you have not bothered to read the forum announcements or to follow the advices in them then the level of help available for you will drop substantially, also known as Murrkf's law.."
WE can not say what is "real" dbGain or not
we would need the equment that People just cant get. and testing conditions we can do or provide.
like the Lockheed Corporation one of the world's largest Aerospace Companies, at their Rye Canyon Laboratory and Antenna Test Range.
All that people go with antenna designs and numbers that have ben arround since the 1920's through the 1950's and what manufacturers provide with there products thats what Most all use .
You Dont Need a Large antenna or a directional to get alot of gain.
With a omni that is a loaded antenna that depends on the "Q" factor of the load that is used.
it depends on the antenna design and efficiency .
and im not saying that the Ebay antennas are True Gain or even good antennas other than
"what the hell" for 10.99 why not try them so i did and have found thay work jus as good as my wifi BiQuad dish and i dont need to keep pointing every place that I might be roaming.
you Only see directional antenna designs all over the internet ONLY cause thare the simplest and Fastest to build .
MOST dont know how to mess with "loading" coils and messen with q factor calculations.
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I used to repeat the signal outside because I like to go outside with my Ipod touch and listen to internet streams but the repeater choked. So currently my WRT54GL router with stock antenna gets a somewhat usable signal if I get REALLY close to the house. So I'm hoping these extend things at least a few feet. I'll let you know if these are any good.
I have a router sitting (unfortunately) in a concrete basement, where it cannot be moved, it is at the back wall of the house, sending a signal across to a 2nd house, probably 500 or so feet away. I do not need signal behind this router, but want to improve the signal in front, in order to be able to remove a middle router that is currently repeating the signal.
The problem is that the 2nd router is uphill from the first, not a huge amount, but from the first router in the basement to the 2nd router there is probably a 50 foot rise over the 500 foot distance. Could I angle the panel antenna upwards slightly to account for this?
The antenna in the link above says it has a 35 degree beam width, is that 35 horizontal? or vertical? or both? Thanks.
