25 dBm Total power output I.E. Using both Chain1 and Chain2
This means
Single chain is more like 22 dB
Dual chain should be 25 dB
The Card rating is also listed as the maximum output, or in other words, you will not get 25 dBm @ Higher modulation rates like MCS-7 or MCS-15 for example. Power output will go down as modulation rates increase with many cards.
If you set the card power to "default" it is usually the most powerful setting you can safely use.
You can then view the table under "Current TX Power" In the wireless tab.
*Note - To see the "Current TX Power" Tab, you must be select "Advanced mode" in the interface main window.
To see more in depth specifications on TX power levels VS modulation rates and sensitivty, you can look at the R52Hn brochure.
http://routerboard.com/index.php?showProduct=94
http://routerboard.com/pricelist/downlo ... ile_id=202
-Brad