"The Natural Philosopher" wrote in message
...
So, how do presumably metal or carbon fibre blades thwacking past or
around a microwave tower affect its transmission and reception?


Not just microwave coms but TV and radar as well...

http://news.bbc.co.uk/1/hi/uk/7227967.stm

http://www.theregister.co.uk/2009/04/03/ofcom_wind/

http://www.bbc.co.uk/reception/info/windfarms.shtml