Thanks everyone for your responses there is a lot of good advice here

Regards

Fred

I was able to remove the hum (of around 150 Hz) completely with MC AudioSuite. I used the EQ 3 1-Band and cut out a smalll band around 150 Hz with Notch.

Butterfly, that cracked it, after a little tweaking with the notch filter I managed to isolate the offending Freq.

Thanks very much.

Fred

posted in error..

Editmvp:

Download the free trial version of Adobe Sound Booth (formally Audition) - it has a very good noise reduction function.

for the record Adobe is still making Audition, now at Version 3. it's a higher-end DAE than Soundbooth. I've been using Audition's NR for many years (it was Cool Edit Pro before Adobe bought it) and it's really good. there's a 30-day free trial. of course if audacity works then it's a winner, being free. there's a comparison of soundbooth and audition here http://www.adobe.com/products/audition/compare/

               ~ sasha