Matt Zilmer wrote: >>The instructions have you clipping one SMT resistor and then removing >>the pieces. >> >>I've did a trial of this method on a junk PCB here. >> >>At least on the board I used, there apparently is some kind of adhesive >>under under the chip. The clipping process seems to remove the solder >>resist and perhaps any PCB traces under the chip. >> >>Is there anything under R8 that can be damaged? >> >>(Guess not, since nobody complaining. A blow up of the pix doesn't seem >>to show anything either) >> >>73 de Brian/K3KO
>The K3 electronics seems to be assembled with a "clean" SMT process, >which means that only solder paste is used to hold the components on >the board during reflow. The boards are designed for rework. > >You should not experience the same problem with K3 PCBA's. I've done >most of the approved rework to the K3 and had no trouble like this. > >73, >matt W6NIA >K3 #24 Good information from the man who knows. But I think it's a bad recommendation for K3 owners to remove SMD components by crunching them up with diagonal cutters. It's a violent process - the cutter blades focus a large force into a very small area - with a significant risk of tearing up the tiny SMD pads and damaging the board. Some boards also have hair-fine copper traces routed *between* the pads. Plow up one of these and you're in real trouble! (Maybe not on the K3 IF gain mod... but one day you'll regret doing it this way.) It is much safer - and also much easier - to 'float' the chip gently off the board by melting the solder on both ends at the same time. As Matt says, the pads are designed for this kind of rework and the resistor comes right off. -- 73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB) http://www.ifwtech.co.uk/g3sek ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
