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-   -   EMI/RFI rejection vs. Ventilation. (

PJD3 11th July 2005 05:21 PM

EMI/RFI rejection vs. Ventilation.
Hello Folks. I'd like to hear some of your feedback on RFI rejection vs ventilation regarding rackmounts for mic preamp modules. I'm about ready to order components from Seventh Circle but I will be using a different rackmount than the prefabricated one offered by them. I do like what they offer but I need to be very cost effective right now, plus I have had experience and good success with electronic projects in the past. I have my eye on a Par-metal rackmount with the increase RFI rejection but of coures there is no ventilation for heat dissipation. For those types of modules as offerered by Seventh Circle, is heat ventilation a more critical consideration than having an improved rejection of RF and EMI? I notice that they use a box that seems well ventilated. That probably hints(or screams) at the answer to my question but I would still like to hear your ideas on this. Is an RFI rejection case even going to make a difference? Can I use a nice big 3U height, 12" depth, spread the modules out and get the best of both worlds? I'm really excited about this project, it's going to cost some bucks and I don't want to introduce anything that will compromise the performance of these preamps. Thanks for your time I look forward to your responces on this. Thanks!

Phil D.

PJD3 11th July 2005 08:12 PM

Ventilation necessary
I just got my answer. These preamp modules and power supply do require ventilation. The vent holes or slots are not regarded as an impediment to good RF shielding at the frequencies that we are concerned with. I guess I shouldn't be surprised!

Thanks all for listening in.

PHil D.

tINY 11th July 2005 11:23 PM

Glad to help...


zmix 13th July 2005 05:00 AM

Have you noticed that a microwave oven can operate safely with a perforated steel door?
This is a very high frequency signal, and it cannot pass through those little holes.

Real studios often have a "faraday cage" which is simply metal screen in the walls and ceiling to block RF.

Solid steel isn't mandatory...