what are those drum shaped antennas on transmission towers called? 1

[alfalfy]

hi,

i have been trying to find out what those drum shaped antennas on transmission towers are called, and whats inside them, does anyone know?

see the pic.
like the drum shaped fellows clearly seen in this picture. btw.

img [

http://en.wikipedia.org/wiki/File:Willans_Hill_Comms_Tower.jpg

]

please help!

thanks in advance, alf.

 

[VEBill]

Parabolic dish reflector (with a cover to keep the weather out).

 

[Comcokid]

Many are made by divisions of Andrew Antennas - see link below.

http://www.commscope.com/andrew/eng/product/antennas/ter_microwave/tmw_antennas/index.html