-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Mark wrote: > On 3/13/08, Chuck Robey <chuckr at chuckr.org> wrote: > >> Yoiu original complaint didn;t seemo to list that you were charging at the >> same time, >> > > Because it's irrelevant; the noise is the same regardless of whether > I'm charging or not, and I did say that it applied in non-automotive > situations, which immediately rules out ground loop anyway. If you were a reliable judge of noise, then you'd be right if it didn't get better/worse when charging, but being in/out of a car hasn't the least to do with it, noise from a charger system doesn't need to come from outside itself (from the car) it can be self-generated by any switching power supply, and they've gotten cheaper and cheaper, which means more and more likely. Someone commented that car stereos don't have this problem; that;'s because those designers KNOW they must operate in that environment, and reasonably (because anyone could tell if they didn't) they design for quiet in such environments. Sometimes, as in computer environments, it's not always so that a key spec is audio level noise, so that can get thru. Ask any engineer, what I'm saying is reasonable. There are two reasons that you say (below) that the ground loop isolator might help noise, and they're both equally likely. One would indeed be ground loop problems. The other would be impedance mismatch problems. You might not care which fixes your problem, but if you jump at the easiest guess, it's going to cost others who hit this problem (and rely upon your assumtions) some woe, if their problem isn't fixed by such a solution, by (for example) a ground-loop-isolation system that didn't incidentally fix the impedance mismatch, something easily possible. I can't tell you which is was, without further testing, but I CAN tell you, from bitter experience, jumping to conclusions that aren't truly justified can really burn the hell out of you. Just don't want to spread FUD. When dealing with noise, it;'s ALWAYS a complicated subject, because there are multiple sources that usually all contribute together. Sometimes, fixing the worst one is enough, but if you're a real stereo enthusiast, well, you get my implication? I'm pleased that your problem is fixed, though, and maybe that's sufficient for you. > > By the way, I have yet to try a ground loop isolator that actually > works. Some do reduce the problem, but they never eliminate it > entirely. The bottom line is that the problem you're trying to solve > with those is with the aftermarket component's poor design and cheap > connstruction, which can't. be fixed with an external gadget. If it > were actually the vehicle, then why is it that factory stereos _never_ > have that problem? There clearly is a design issue that the > aftermarket engineers are ignoring. > _______________________________________________ > maemo-users mailing list > maemo-users at maemo.org > https://lists.maemo.org/mailman/listinfo/maemo-users -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFH2sI1z62J6PPcoOkRAiHZAJ9ZKhqjoHlDZYh2Q32c+d0SWVyo/gCgnMhb eAJav8yQfiJB2fA0GJbKo+0= =Ntb5 -----END PGP SIGNATURE-----
