And before someone says 'with a tape', my problem is this. I bought a product described as a Raven 60cm sky region 2 dish on ebay. When it arrived it measured 75cmx55cm and is visually too big for my freind for whom I was to install it. I have questioned the seller over this and they assure me that the '60cm' is a calculated effective dish size related to its gain. This he tells me he has been advised by Raven, the company. Is this chap right about this? Any help appreciated. Regards to all.