mungoh wrote:
I thought that there was a factor of ten between inside the roof and
outside the roof?

I looked at http://www.wrightsaerials.tv/, which I saw here, or
some digital TV group - there's some good stuff there, for instance:
http://www.wrightsaerials.tv/digitalterrtvrecep.htm. There's also
http://www.wolfbane.com/cgi-bin/tvd.exe? and so on.