K2 #4309 on the air (finally)
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I finished the basic kit after 40 hours. Had no problem until it came to transmitter alignment. No output at all. After toroid checks and some signal tracing I discovered a broken D36 (fragile). A $8.75 and 6 days shipping experience :-) Although there's documented that it's fragile builders maybe should be advised how to handle D36. Absolutely no force to the glass body would be a nice hint in the manual. So I replaced the D36 with a 1N4007 for transmitter alignment and everything worked fine. Couldn't help but had to get in the air once - just to be sure. Worked Italy on 20m with 3m of wire connected to my KAT2, which I had built in the meantime. Last weekend I added the Battery Option as well as the Noise Blanker and will test the whole kit next weekend. Another 10 hours including the KAT2. Had a strange thing once. The filters misaligned themselves. The middle frequency suddenly was a few hundred hertz too high. I reran 4MHz, PLL, BFO and filter calibration/test and everything was fine again. Although I don't know what caused this problem. I hope it doesn't occur regularly in the future. And: TX power decreases slowly when frequency rises. Only abt. 9W on 10m with 14 on 20m. So, this was my first kit - and will probably not be my last. Thanks Eric and Wayne - and Scott for the D36! 73 Gerhard DH3FAW K2 #4309 www.gs-personal.de _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
Re: K2 #4309 on the air (finally)
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My observation with D36 is that attempting to bend the leads close to the
glass body (like most of the other diodes) can cause the glass to fracture. The holes for D36 require the leads to be bent approximately 1/8 inch from the body, and if the leads are bent right up to the glass, there will be a lot of excess stress placed on the diode when attempting to insert it into the holes. Bottom line - bend the leads a bit away from the glass body - use the hole spacing as a guide to determine just haw far that 'bit' really is (I haven't really measured it) - as an alternative, don't bend the leads at all, just solder them to the solder pads on the bottom of the board without inserting the leads into the holes. 73, Don W3FPR Life is what happens when you are making other plans ----- Original Message ----- I finished the basic kit after 40 hours. Had no problem until it came to transmitter alignment. No output at all. After toroid checks and some signal tracing I discovered a broken D36 (fragile). A $8.75 and 6 days shipping experience :-) Although there's documented that it's fragile builders maybe should be advised how to handle D36. Absolutely no force to the glass body would be a nice hint in the manual. _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
Re: K2 #4309 on the air (finally)
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Use a small set of needle nose pliers to hold the lead in place next to
the glass body, then bend. Don't hold the glass body and bend. The pliers will become the stress point, not the glass body. bb n6iz Don Wilhelm wrote: >My observation with D36 is that attempting to bend the leads close to the >glass body (like most of the other diodes) can cause the glass to fracture. >The holes for D36 require the leads to be bent approximately 1/8 inch from >the body, and if the leads are bent right up to the glass, there will be a >lot of excess stress placed on the diode when attempting to insert it into >the holes. > >Bottom line - bend the leads a bit away from the glass body - use the hole >spacing as a guide to determine just haw far that 'bit' really is (I haven't >really measured it) - as an alternative, don't bend the leads at all, just >solder them to the solder pads on the bottom of the board without inserting >the leads into the holes. > >73, >Don W3FPR > >Life is what happens when you are making other plans > >----- Original Message ----- >I finished the basic kit after 40 hours. Had no problem until it came to >transmitter alignment. No output at all. After toroid checks and some signal >tracing I discovered a broken D36 (fragile). A $8.75 and 6 days shipping >experience :-) > >Although there's documented that it's fragile builders maybe should be >advised how to handle D36. Absolutely no force to the glass body would be a >nice hint in the manual. > > > >_______________________________________________ >Elecraft mailing list >Post to: [hidden email] >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 > > > > _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
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In reply to this post by Don Wilhelm-2
>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: [hidden email] 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 |
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Like Brian, N6IZ I favour the method of holding the leads of the K2's D36 in
needle nose pliers then bending the wire end with finger pressure to form a smooth bend to the required hole spacing. Bending the leads directly with needle nosed pliers alone would be really asking for trouble by the increased stress on the diode body. The same rules apply to all other fragile small components which could be damaged by stress. Agreed, other relatively more robust diodes such as the 1N4148 and similar are able to have their leads bent with finger pressure alone without any apparent ill effects. All a matter of learning by experience of what is permissible and finding out the hard way what is not. Bob, G3VVT K2 #4168 _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
RE: Bending component leads
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I never hurts to be more careful, unless it causes other problems such as
breaking the lead or the part because it's being held by needle nose pliers. I've yet to break a glass diode (or other part) by gently bending the lead while holding the part and letting the lead take up its own radius of bend. I couldn't say how many hundreds (or thousands) of such parts I've handled since I picked up my first glass diode some decades ago. What is dangerous, and I've seen it happen in labs where someone is trying to work too quickly, is holding the lead with pliers up against the body, and then bump the body or the opposite lead. There's TREMENDOUS force placed on the body of the part if that happens. It'll snap one end right off of a glass diode. I prefer soft fingers to hard steel when working around fragile parts. So whatever system you use, be g-e-n-t-l-e and don't work when you're in a hurry or tired. I'd guess that the biggest source of all errors in building is trying to work quickly or when tired. Ron AC7AC -----Original Message----- I favour the method of holding the leads of the K2's D36 in needle nose pliers then bending the wire end with finger pressure to form a smooth bend to the required hole spacing. Bending the leads directly with needle nosed pliers alone would be really asking for trouble by the increased stress on the diode body. The same rules apply to all other fragile small components which could be damaged by stress. Agreed, other relatively more robust diodes such as the 1N4148 and similar are able to have their leads bent with finger pressure alone without any apparent ill effects. All a matter of learning by experience of what is permissible and finding out the hard way what is not. Bob, G3VVT K2 #4168 _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
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In reply to this post by G3VVT
I ALWAYS grip the component with thin needle nose pliers against the body
before using a bending jig or my fingers to move the leads 90 degrees to the case of component. I have seen diodes fracture if not. 72 Stuart K5KVH _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
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In reply to this post by G3VVT
What's wrong with simply holding the diode body
between thumb and forefinger and bending the lead against your thumbnail? de Joe, aa4nn _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
RE: Bending component leads
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The idea is to avoid any undue pressure on the attachment of the lead to the
part - especially with glass diodes. I've always simply bent the lead, making sure it was free to take up its own natural radius that depends upon the stiffness of the lead. I hold the body in one hand and push the end of the lead with my other hand. I've never lost one yet doing that, but others report they have broken glass diodes unless they carefully support the lead with needle nose pliers where it exits the body of the part. It sounds like what you are doing is similar to get a tighter bend. The lead forms a lever with your thumbnail at the fulcrum, working against the body of the part as you bend it. It will increase the strain on the part somewhat, depending upon how close to the part you put your thumbnail and how much force is needed to bend the lead. I don't know that it'd be enough to break a diode. On the rare occasion when my method didn't produce a tight enough bend to fit the holes in the PCB, I've squeezed the bent leads near the body of the part gently to make the radius of each bend smaller. I'd suspect that puts the same sort of strain on the diode that your method using a thumbnail does. Have you ever broken a diode that way? I haven't....yet, Hi! Ron AC7AC -----Original Message----- What's wrong with simply holding the diode body between thumb and forefinger and bending the lead against your thumbnail? de Joe, aa4nn _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
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Ron and all,
I bend component leads just like Joe - hold my thumbnail where I want the bend, grasping the component between the thumb and forefinger. That method has not broken any so far. I have only broken a part when I approach them with something hard like pliers. Each to his own! Occasionally the 1N4148 diode holes in the K2 require one to bend the leads quite close to the body of the diode, and I sometimes think the thickness of my thumbnail is too great <G>. When that happens, I usually just form the leads a bit and settle for not getting the diode right down on th esurface of the board - close but not flat on it. 73, Don W3FPR Life is what happens when you are making other plans ----- Original Message ----- The idea is to avoid any undue pressure on the attachment of the lead to the part - especially with glass diodes. _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
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In reply to this post by Joe-aa4nn
G'day,
<> What's wrong with simply holding the diode body between thumb and forefinger and bending the lead against your thumbnail? de Joe, aa4nn <> Nothing, it works perfectly, every time. Regards, Mike VP8NO #1400 et al _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
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In reply to this post by Joe-aa4nn
The parallel jaws of extremely thin needle nose pliers will grip the lead by
the body of a part and resist the bending forces at 90 degrees to the wire lead that might cause internal stress on diodes or other component terminations inside a part. The jaws have cross wise serrations that get a firm grip on the component wire lead. This is particularly helpful with point contact diodes, and certain other parts. The smaller leaded components such as 1/10 watt resistors can also fracture if you do not hold the lead against the body before bending at 90 degrees. -Stuart K5KVH _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
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