>From comments about broken diodes and other issues, it sounds like some builders may be using needle-nose pliers to hold the lead near the body of a part and rotating the pliers to produce a small-radius bend in the leads where they exit the body of the part. That's never a good idea because it puts a lot of strain on the body of the part. The insulation on resistors can be chipped easily that way. Even capacitors can be ruined doing that. The little molded epoxy caps are actually surface-mount type caps with leads soldered to them and the whole assembly dipped in epoxy. Surface-mount parts aren't designed to have a lot of mechanical strength. The "terminals" are usually soldered directly to a PC board. So when they are used with leads attached, the epoxy coating provides all the mechanical strength to avoid strain on the cap inside. Break that epoxy loose and any strain on the leads is strain on the capacitor inside. That can produce an open or intermittent capacitor.
As several builders have discovered, it's very easy to crack and ruin glass diodes as well. I always bend the lead by hand, allowing the lead to form a natural radius curve near the body by holding the body with the fingers of one hand and bending the lead by holding it well away from the body with my other hand. If the leads turn out to be slightly too far apart, a gentle squeeze will make the bend radius a little smaller without putting excess strain on the part body. On the rare occasions where the hole spacing is substantially wider than the length of the part, I do hold the lead in needle-nose pliers with the pliers covering the length of lead near the body that I do not want to bend. I then bend the lead using the fingers of my other hand, not by rotating the pliers. Laying the part on the PC board first to check the spacing of the holes will give you an idea how close to the body the lead bend needs to be. I've never found it a good idea to use needle nose pliers to make a very small radius bend in the leads except when absolutely necessary on a very crowded board. A sharp-angle bend puts a lot of strain on the lead itself, if not the part. If you make a mistake and need to straighten the lead and re-bend it in a slightly different place, you may find that the lead has cracked and may break off at the bend. Ron AC7AC _______________________________________________ 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
