I hate to be the bearer of bad news, but you're going to need at least 4 dongles to cover that entire site, possibly 5 depending on how busy the site actually is. If it's not a very busy site, you may be able to get away with 3 dongles, allowing two of them to retune as necessary. But if it is a busy site, to cover every frequency, you'll need 4-5 dongles.