I own a Bush 14" Portable TV (and I dont need to tune in the channels as I have got Sky) and this is the method that I used when we didnt have Sky.
1. Plug in a portable or outdoor aerial.
2. Go to the menu on your TV.Then go to CH (or Channel) Tuning and search for signals. (Note: If it is a crap signal, ignore it and see if you can get better one. If the signal is really crap the TV will usually ignore it.)
Hope this had helped
Chad Bronson
May 2006