To get a better picture, see a standalone AP WebUI under Configuration::Radio
2.4 or 5G, and from Common Settings, if you drop-down the Transmit Power list,
Full power corresponds to the full radio and antenna combined output. The scale
drops by -1dB, following RF math, and -3dB corresponds to Half the tx power as
The scale continues for -10dB, and shows (Quarter) at -6dB, (Eighth) at -9dB.
You see a -10dB, and finally a Minimum choice, which is the lowest tx power we
can turn the combined radio/antenna to, in order to limit the distance of RF
coverage. Different model APs have different inherent radio/antenna power.
You see this reducing output power under ZD managed APs, from Configure/
Access Points, under the Access Point Group. TX Power drop-down includes the
Full down to Min options as a standalone AP, but also includes the 'Auto' choice
which submits the AP to the ZD's self-healing power/channel algorithms or
overrides, as you describe them.