Derek, there is a big difference between military/Tempest equipment and commercial equipment. I have used honeycombe filters in Tempest designs because of the very low limits. But, In my 30 years of design experience of point-of-sale equipment, mini-computers, PCs, and other types of business equipment, I have never seen the need for a honeycombe panel to comply with commercial EMC limits. Even if there were a need, it could never be cost justified. Rather, it would indicate that the digital designers did a very poor job of source suppression and a pcb redesign would be ordered.
Richard Woods Sensormatic Electronics [email protected] Views expressed by the author do not necessarily represent those of Sensormatic. > ---------- > From: [email protected][SMTP:[email protected]] > Reply To: [email protected] > Sent: Tuesday, July 21, 1998 11:33 AM > To: [email protected]; [email protected] > Subject: Re: Desiging Openings for EMC Compliance > > Jim, > > you hit the nail on the head, even with extensive calculations, the error > is > large. Seasoned EMC chaps tend to ask for thin-walled Honeycombe openings > with > a depth at least 5 times the hole dia. If you can't live with a deep hole, > life gets hard.... > > Derek Walton > Owner: L F Research EMC Design and Test Facility, Poplar Grove, IL USA. >
