[Amps] Holes vs. screen for chassis ventilation?

[Jim Brown]

  On 10/6/2010 5:45 AM, TexasRF at aol.com wrote:
> 1>  the old Bill Orr Radio Handbook has a chart showing rf attenuation vs
> hole size in the section dealing with rfi and shielding  considerations.

There is a detailed set of relatively simple design equations for the 
relationship between hole size and RF leakage vs frequency in all 
versions of Henry Ott's excellent texts on EMC.  I'm working with 
editors of the ARRL Handbook to get this material in that book. Yes, it 
is VERY important that the opening consist of small holes to maintain 
shielding.

The latest edition of Henry's book (the third) is a must have for anyone 
concerned with electronic design. NOT filled with math, very practical. 
Henry is a ham, don't remember his call.

http://hottconsultants.com

73, Jim K9YC