I am looking for those sort of triangle TEM cells to do a wuick over the air testing for mobile phones. I have found www.temcell.com model 5060B as a vendor but I cannot find another vendor evendoing a google search for TEM cells. I know ETS-lindegren has some RF boxes but was not sure if there was any other vendor.
My company uses a GTEM cell from Schaffner. Take a look to see if it is useful to you... http://www.schaffner.com/test_systems/en/product/tsyssecondelevel11.asp?level=3$2$12&language_id=12