Well, I don't know about wifi radar, but you have to edit your /etc/rc.d/rc.inet1.conf file. Here's an example:
Code:
# Config information for ath0 (using dhcp):
IFNAME[1]="ath0"
IPADDR[1]=""
NETMASK[1]=""
USE_DHCP[1]="yes"
DHCP_HOSTNAME[1]="mywirelessbox"