Your Netgem TV device is capable of receiving over 135 Freeview Channels with 15 channels in HD. However, the exact number of channels available to you is dependent upon location, tall buildings, trees and hills. To get an accurate indication of how many channels you can get, it is best to use the Freeview Checker developed by Freeview themselves.
You can also strengthen the number of channels available to you by installing a rooftop aerial. If you would like to install a rooftop aerial, get in touch with either the Confederation of Aerial Industries (CAI) or Get Me Digital. You can find an approved CAI installer at www.getmeviewing.org.uk or find a digital professional at www.getmedigital.com. A local installer will understand the circumstances and local geography in your area and will suggest the best option for you.