Search found 12 matches

by Gertjan
Thu Jun 05, 2014 12:58 pm
Forum: Pro Audio Design
Topic: RFI protection concepts
Replies: 48
Views: 121576

Re: RFI protection concepts

Wayne, thanks for your insights.

It is a privilege to be able to discuss matters with much more experienced people.
Their level of expertise goes far beyond textbooks & application notes, gained by decades of hands-on design.

Most appreciated!

Regards, Gertjan.
by Gertjan
Mon Jun 02, 2014 11:58 am
Forum: Pro Audio Design
Topic: RFI protection concepts
Replies: 48
Views: 121576

Re: RFI protection concepts

Back to the topic of RFI protection. I took a hard look at the THAT recommended Y configuration for the RFI C's: From THAT 1240 datasheet, and from my concept: https://www.miedemageluid.nl/images/web/Y-caps-THAT_1240-Datasheet.jpg http://www.miedemageluid.nl/images/web/2x-Cap-GJM.jpg I appreciate th...
by Gertjan
Mon Jun 02, 2014 10:55 am
Forum: Pro Audio Design
Topic: RFI protection concepts
Replies: 48
Views: 121576

Re: RFI protection concepts

You’re both right of course. The separation between clean audio ground, keeping supply currents out is always on my mind when doing a PCB layout. (Often it is the hardest part to get right). But I never draw it in my Schematics. For a Concept, this is a better representation: https://www.miedemagelu...
by Gertjan
Sun Jun 01, 2014 12:12 pm
Forum: Pro Audio Design
Topic: RFI protection concepts
Replies: 48
Views: 121576

Re: RFI protection concepts

Here is my new concept for Grounding and RFI protection: https://www.miedemageluid.nl/images/web/RFI-protection-concept-v5.jpg - For grounding I am following AES 48-2005, but Star Grounding as much as possible. - For RFI protection I treat the Case as a Cage of Faraday, decoupling all incoming leads...
by Gertjan
Fri May 30, 2014 4:02 pm
Forum: Pro Audio Design
Topic: RFI protection concepts
Replies: 48
Views: 121576

Re: RFI protection concepts

JR,
I really had to laugh when I read your Mexican anecdote!
Gertjan.
by Gertjan
Fri May 30, 2014 10:58 am
Forum: Pro Audio Design
Topic: RFI protection concepts
Replies: 48
Views: 121576

Re: RFI protection concepts

Indeed I am reading Henry Ott, Neil Muncy, Bill Withlock, Jim Brown. Most out of my own library. Amazing how much one can forget.... The Hart of the Matter: Neil A. Muncy, 1995: https://www.miedemageluid.nl/images/web/Neil-A-Muncy-1995.jpg AES 48-2005 Standard in a nutshell, 2005: https://www.miedem...
by Gertjan
Fri May 30, 2014 4:26 am
Forum: Pro Audio Design
Topic: RFI protection concepts
Replies: 48
Views: 121576

Re: RFI protection concepts

Ricardo – In a film sound bag all gear (mixer, recorder, radio mike receivers) has it’s own lead to the Battery (or power distribution). That’s why the galvanic isolation in de Power Supplies is helpful. Indeed “modern evil digital” introduces new problems! Some Boxes radiate RF up to the frequencie...
by Gertjan
Fri May 30, 2014 3:16 am
Forum: Pro Audio Design
Topic: RFI protection concepts
Replies: 48
Views: 121576

Re: RFI protection concepts

JR – Of course you are completely right! And my schematic is certainly not in accordance with the AES48-2005 directions. Ricardo already touched this weak spot: This is a good scheme. The only caveat might be you have Chassis 'directly' connected at both i/p & o/p. This might give a hum loop but...
by Gertjan
Thu May 29, 2014 5:21 am
Forum: Pro Audio Design
Topic: RFI protection concepts
Replies: 48
Views: 121576

Re: RFI protection concepts

This is a good scheme. The only caveat might be you have Chassis 'directly' connected at both i/p & o/p. This might give a hum loop but it depends on loadsa other stuff ... like what's connected. Probably OK if its an all portable system. I like direct connection to Chassis at the outputs (main...
by Gertjan
Wed May 28, 2014 4:19 am
Forum: Pro Audio Design
Topic: RFI protection concepts
Replies: 48
Views: 121576

Re: RFI protection concepts

Gentleman, I really feel honoured with your detailed insights, and appreciate your effort, especially Ricardo’s Main point from Ricardo is that One should think in terms of shorting RF to Chassis / Case, shunting the RF around the circuit. And not think in terms of filtering Inputs / Outputs. I am a...