There's masses of info on cables here:
www.belden.com
click on products, then Belden catalog and the technical info.
RG-59, RG-6 and RG-11 are just different classifications of cable. There are plenty of options within each class although they are broadly similar. Belden call them Series-59, Series-6 etc. I'm not sure which manufacturer NTL uses - probably not Belden as they are probably the most expensive!