again, it's just a noise filter! you can easily get by just jumpering wires from one side to the other, or 47 ohm resistors. the problem with the original part is not that it's custom, it's that the apple engineers weren't paying enough attention, it sometimes operates at twice it's rated wattage! this will seriously shorten the life of any part! if you really, really want a filter, a better, more effective, and more reliable solution is as follows, get 12 of the L-C-L filters from digikey, bend the middle wires to the side, solder the end wires into each pair of holes where the original was (you will have to bend them out slightly since the end wires are 0.2" apart and the pads are 0.3" apart), ignoring the pair on each end which were ground connections. solder the middle wires together, and connect to one of the available ground connections at one or preferably both ends. this design filters better, produces less signal attenuation, and dissipates nearly zero power so is much more reliable. the filter part number i would recommend for this is digikey part number:P9808CT-ND (30 cents ea.), or for surface mount, in which case you can use a single sided board, digikey #:P9831CT-ND (though any of them would likely work just fine, check the catalog pages for a graph of the frequency response). myself, i'd just use a 1.4w 47 ohm resistor or jumper them, if you're in the mood you could add a ferrite bead, digikey #:M2303-ND, preferably on the mac side of the signal line, but honest, a jumper or a resistor will work just fine (with resistors it's easier to avoid shorting signals together, and might work a little better with local talk connections as it provides the "source" resistance, but i'd be surprised if you could tell the difference. if i were worried about RFI, i'd use the digikey L-C-L pi filters, i've used them before on analog and digital signals and they're great! i certainly wouldn't waste money having a board made, if you wanted to, you should be able to do it with a home made single sided board with surface mount, or a double sided board with the whole back side being a ground plane, if you simply must make it hard on yourself.
> I whipped up a little design in Osmond PCB using 0805 size resistors > and capacitors. It might make more sense to use a pair of eight > resistor networks such as DK part # 4816P-1-270-ND. > -- "There are reminders to all Americans that they need to watch what they say, watch what they do, and this is not a time for remarks like that; there never is." White House Press Secretary Ari Fleischer, how much blood will it take to win back the first amendment, which the Bush administration clearly does not support! The thought police are amongst us. -- Compact Macs is sponsored by <http://lowendmac.com/>. Support Low End Mac <http://lowendmac.com/lists/support.html> Compact Macs list info: <http://lowendmac.com/lists/compact.shtml> The FAQ: <http://macfaq.org/> --> AOL users, remove "mailto:"; Send list messages to: <mailto:compact.macs@;mail.maclaunch.com> To unsubscribe, email: <mailto:compact.macs-off@;mail.maclaunch.com> For digest mode, email: <mailto:compact.macs-digest@;mail.maclaunch.com> Subscription questions: <mailto:listmom@;lemlists.com> Archive:<http://www.mail-archive.com/compact.macs%40mail.maclaunch.com/> --------------------------------------------------------------- >The Think Different Store http://www.ThinkDifferentStore.com ---------------------------------------------------------------
