> Like it or not, we are seeing another transition in kit building. Just > as some of us witnessed the transition from tubes to transistors, we > are now seeing the beginning of the transition from parts with leads > to SMT. I would guess that in ten years or so it will be > increasingly difficult to find parts with leads.
There's a fundamental difference between the two watershed moments you describe. The shift from tubes to transistors brought new capabilities. These were primarily the result of the need for less power and the dramatic change in size. Being able to do the same thing in a smaller package that required less power and dissipated less heat brought about lots of innovation. The shift from leaded parts to surface-mount parts is different. It is a change of form to accommodate automated assembly. There is some change in size but overall it's the same stuff in a different-looking package. There are things the old parts can do that the new ones can't. For example I have resistors in my airplane soldered inline with fuses. It would be impossible to replace this with a leadless part and impractical to design a circuit board to hold a resistor and a fuse for the sole purpose of using a surface-mount part. One could argue that the shift from tubes to transistors is no different. Transistors weren't plug-n-play compatible with the tubes they replaced, so it was probably imagined that tubes would be around for a while. The problem is that there was no application (other than repairing existing units) where tubes had an advantage. In the case of leaded vs. leadless parts, there are clear examples of the benefit of keeping around the old human-handlable parts. Surface-mount is the antithesis of kit building by its very nature. The devices were built for the very purpose of being installed onto circuit boards by machines, not people. Kit building is driven precisely by the desire to create something by hand, without the use of machines. This is (one of the reasons) why I don't get excited when I see kits like the Sienna (www.getboost.com/dz). It's all preassembled. Surface-mount technology has been in practical use for a very long time and hasn't yet supplanted leaded parts. I can imagine there could come a time when it won't be financially practical to manufacture every variety of IC in both SMT and DIP formats, I'm having a harder time imagining leadless resistors and capacitors replacing their leaded counterparts. Write back in ten years and we'll see how it turned out. :-) Craig NZ0R K1 #1966 K2 #4941 _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
