5 dBi > 9 dBi large upgrade?

[Dolby]

Hi,

Does the antenna figure work logarithmically? Is this a large upgrade?

 

[bdt]

Yes, 3dBi is a half or double, depending on direction from base measurement; so for you that translates to a wee bit more than a power doubling.

 

[Trybble]

Just remember to turn your transmit power down appropriately. Assuming 2.4GHz, the maximum allowed is 100mW EIRP (Effective Isotropic Radiated Power) which, given that antenna gains are expressed in dBi (decibels relative to an Isotropic antenna) is easy to work out:

100mW = 20dBm (decibels relative to 1mW)

20dBm TX + 9dBi antenna = 29dBm EIRP = excessive output (800mW EIRP).
11dBm TX + 9dBi antenna = 20dBm EIRP = legal max.

The above is a bit of an oversimplification since it ignores the presence of losses in a feedline, if you're using one.

*Trybble

 

[Rocket-Boy]

Just remember to turn your transmit power down appropriately.

Sadly most people are not doing this and are congesting the 2.4GHZ spectrum with noise. I dont think you can alter the output power on most commercial AP's and wifi cards etc. From what i know its only really units like your routerboards and linux based routers that give you access to modify output power.

It would be alot better for people who are legitimately trying to use their equipment if everybody complied with the rulings tho :/