EMC and RF Immunity

I have just had an interesting experience of having some severe noise issues on a small micro controller. In the end it was mains hum and a speed drive (located very close by) causing the hiccups.

Anyway I started wondering if there is a reasonable affordable way of doing some testing for EMC and RF issues.

Most of what I have found on the net is at the very wrong end of the cost scale, however I found this hand test tool at www.empulse.co.uk

Anyone got some real life experience in this field they would want to share and some suggestion for testing

Any sort of spectrum analyser can be used, I know these are not cheap but you can make some low cost ones with radio modules. I think there was one in the exhibition section recently.