CE pre-compliance testing: Converting an oscilloscope into a spectrum analyzer?

[Pack34]

I made the necessary changes to what I "think" should improve the overall performance and get the product to pass but I have no way to do any real testing without taking it to someone or buying a spectrum analyzer.

I have a nice agilent o-scope that has what I think to be a really good FFT measurement. Would it be as simple as attaching an antenna to an amp and plugging it into my scope to get a general idea of what I'm looking at. This wouldn't be to replace pre-compliance testing but a way to quickly validate in-house that "this change makes it works" and "this change makes it better." To get some immediate feedback.

I've found some cheap $100 USB ones but I'm not sure I would trust it as much as if I could get my o-scope to do it.

Would this work? Or should I just look at picking up a cheap spectrum analyzer off of ebay?

[Neilm]

You may not need the amp - it would have to be a good one that would work at many MHz. It is possible to make a small antenna from a piece of wire and plug directly into the scope. Even the scope probe just lying next to or nearby can pick up enough information. That being said, small antenna kits are not that expensive.

[KJDS]

You'll save a huge amount of time and effort picking up a spec ana