Thanks to everyone who replied. It seems that small yagis and quagis are OK in roof spaces provided that the liner underneath the roof tiles is not metalised. Contrary to my expectations, rain and snow on the roof doesn't cause problems. DH5MK has some nice pictures of his attic antenna installation on his web site.
73 John G7HIA _______________________________________________ Sent via amsat...@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb