I am trying to get an Alfa Tube-U(N) USB Wifi adapter to work with Ubuntu 14.04.1 and getting stuck with actually connecting to any networks.  It uses the Ralink RT3070 chipset (I think, based on lsusb output), and seems to be loading the rt2800usb kernel driver when plugged in on boot.  An adapter wlan0 shows up when I run iwconfig but I cannot seem to configure it and it says "no wireless extensions".  It does not show up under ifconfig.  Here is the output from some relevant commands:
Lan Setup (other devices removed):
$iwconfig
wlan0     no wireless extensions.
Usb Devices:
$lsusb
Bus 002 Device 002: ID 148f:3070 Ralink Technology, Corp. RT2870/RT3070 Wireless Adapter
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Kernel Modules:
$ lsmod | grep rt
rt2800usb              16519  0 
rt2800lib              78222  1 rt2800usb
rt2x00usb              11505  1 rt2800usb
rt2x00lib              46976  3 rt2x00usb,rt2800lib,rt2800usb
mac80211              477705  3 rt2x00lib,rt2x00usb,rt2800lib
cfg80211              424381  2 mac80211,rt2x00lib
Dmesg output relevant to this device (upon boot):
[   16.606242] usb 2-1: new high-speed USB device number 2 using musb-hdrc
[   16.764023] usb 2-1: device v148f p3070 is not supported
[   16.827013] usb 2-1: New USB device found, idVendor=148f, idProduct=3070
[   16.827042] usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[   16.827055] usb 2-1: Product: 802.11 n WLAN
[   16.827067] usb 2-1: Manufacturer: Ralink
[   16.827079] usb 2-1: SerialNumber: 1.0
[   19.396334] usb 2-1: reset high-speed USB device number 2 using musb-hdrc
[   19.821473] usbcore: registered new interface driver rt2800usb
I'm not sure how much it matters, but I am running this on a BeagleBone Black using the armhf version, as described here: http://elinux.org/BeagleBoardUbuntu#BeagleBone.2FBeagleBone_Black
