The point I am making is that some of the Tv transmissions are weak.
Not that they are weak and can not be received.
The point is that the antenna needs to be up high in the clear to get good signal reception.
Not in the attic where reception will be reduced.
And Yes for testing , some one can get up on the roof and hold the antenna.
Or just stand a tripod antenna mount on the roof to mount the antenna on while testing reception.
Here is a picture of a tripod antenna mount ,
http://www.ronard.com/909911.html.
Or put a chair up the roof and put the antenna on the chair for testing reception.
Try ,
http://www.angieslist.com , or ,
http://www.servicemagic.com. for antenna installers.