To: "'Xylo-SDR Discussion'" <xylo-sdr@lists.ae5k.us> Sent: Wednesday, December 14, 2005 11:56 AM Subject: Re: [Xylo-SDR] Xylo
FolksEvery day I carry my Xylo around and pop it out when I have time. YesterdayI got the Wolfson parts and DANG this is gonna be a problem! These thingsare SMALL! How in the heck are we going to prototype these things? I grew upin a world of leads and vacuum tubes! (smile). I searched around for carriers and stuff and everything seems pretty expensive for these smallparts. We could produce a run of inexpensive carriers with caps and criticallead length components on the carrier. We gotta do something to make it a little easier to handle these itty bitty peppercorns! I know that Bill - KD5TFD has done a lot of this and has some small prototype board sources.
I make my own PCBs, and often make my own adapters for small chips like that, instead of buying them. I use a stereo microscope for the very fine-pitch devices, but most of the time a bench magnifier is OK. 'Drag' soldering is the best technique for soldering chips like that, I have a special mini-hoof tip for my Metcal soldering station that holds a small amount of molten solder and is then wiped across a row of pins, after applying plenty of gel flux. Much the same can be done with a largish soldering iron tip, with a blob of solder on it, but a lot more cleaning up with desolder braid is required.
My Cyclone II chips should be delivered today, I see from the tracking info that they are on the van coming from their London depot.
Leon -- Leon Heller, G1HSM leon.heller@bulldoghome.comhttp://www.geocities.com/leon_heller
---[This E-mail has been scanned for viruses but it is your responsibility to maintain up to date anti virus software on the device that you are
currently using to read this email. ]