Thorn

Q: Is a $20 5.5dBi (or 7dBi) antenna as good as a $60 5dBi antenna?

A: Short answer: No, in fact it's a lot worse.

Every three days or so, someone discovers these cheap antennae on the web. They then come to these forums and ask about them. These antennae are usually rated at 5.5 and 7dBi. They have a small magnetic-mount base, a small diameter cable (~0.10") and look like the picture below.

Bottom line: These antennae are poor performers, and are priced accordingly.

There are a number of reasons for this: The principal problem with them is that they have a very poor cable. Due to the cable type, there is a very high amount of loss of the radio signal. The second problem is that they do not have a built-in ground plane, which results in even less signal getting through to the antenna. The ground plane issue can be overcome by using the antenna on at least a one-square meter metal surface. However, only thing that can be done with the cable issue is to accept it. Due to the construction of the base, the cable is almost impossible to change without damaging the antenna.

Ultimately, these antennae will produce no signal gain above the average wireless card's internal antenna. This is known as unity gain. When used without a metal ground plane, these antennae have reportedly produced a loss. Unity gain can be advantageous where a car body will completely block the signal, as you will get results similar to that as if the car body was not there, but you won't get the results of a more expensive antenna.

Like many things in life, antennae are one of those things where you get what you pay for. If you know the limitations and are willing to accept them, these antennae can be acceptable. However, if you believe that a $20 antenna can and will perform at the same level as a $60 antenna in the same gain range, you will be sorely disappointed.

Attached Images

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Thorn
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