Reducing RF noise from computer

In my office I have a pair of iMacs and my Windows machine (HP Pavilion Elite). The iMacs are fairly quite RF wise but the Windows machine spews a lot of RF noise to my scanners.

I use a half dozen BCT15's in Search mode, 4 for the Mil Air band (each in a different segment) and 2 on Low band. Occasionally I also use a couple other BCT15's or BCT15X's to search aviation or rail bands.

When the Windows machine is off I get one or two freqs per scanner with noise but when I turn on the Windows machine there are dozens on all parts of the MilAir and VHF-Low bands.

Is there anything I can do to help reduce the noise output of the computer? It already has a mostly metal case. I would try to move it away from the radios but there are limits due to the interconnection of the radios to the computer (its main purpose in life...).

I had considered a rack mount computer to replace this box or rebuilding the existing one into a rack mount box but now I am having second thoughts about that...

You could spend a lot of time with ferrite beads, changing power supplies, turning things on/off.... I'm sure you'll get a lot more suggestions here. There are other possibilities e.g. cable modem, DSL modem, cheap Ethernet cables, AC "wall wart" power supplies for speakers, etc. It sounds like you've narrowed it down to the Windows computer. So you're probably looking at getting a different (new) Windows box. Something I do when I'm computer shopping is to take my handheld scanner loaded up with a mix of VHF / UHF freqs, AM airband freqs, etc. Turn it on and put it right next to the computer you are thinking of buying to see what level of RFI / EMI is coming from the computer.

first thing to check in a RF Noise environment for a PC is PSU. next comes Monitor. and any Power Bricks. ( AC Adapters )