Am Sa 20. September 2008 schrieb Werner Almesberger: > But that's something you'll have to solve anyway. Otherwise, even > the nicest CMU200 will be of little use.
Well it's a little different to run a certified GSM-phone on a CMU200 which itself is at -80dBm, or to run a selfmade 2W-oscillator ;-) Though the result is the same from a technical point of view. > > > > Basic guidelines: > > Good principles for sure. > > > > All connectors to outside of housing SHOULD have EMI-filters [[edit: as > > > close as possible to component]] on all lines > > Shouldn't the EMI filters rather be where the signals enters the cage ? Actually these "quick-and-dirty" specs require both. It's arguable whether we can save one of them. The spec was done to *guarantee* a clean buzz-free design, rather than with BOM in mind ;-) > > > > *) that's one of the points why it's more reasonable to have a separate > > > cage. > > Hmm, makes the mechanical setup more complex, though. Marginally. We could have another tin-wall inside the current can, forming two separate compartments. > > > > We don't want the need for EMI-block on lines that aren't related to > > > audio, but run to same cage. > > Shouldn't they be filtered anyway, lest we contaminate other signal > paths, e.g., hyper-sensitive GPS ? Hm, guess I don't get it. Idea is to block all RF from entering can. Clock-harmonics and the like are a completely different story, and also the clock frequency itself could create noise if a clocked component is placed inside audio can, not only it's harmonics. /j
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