Neurotic about Toroids
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I am still considering what my *grown up* rig will eventually be after I've outlived my
*first* rig . I always seem to go back to the K2 and that is where my head and heart are. But the devil keeps popping up, whispering in my ear that I'll never be able to strip and mount so many toroid coils (and that I'll probably zap an IC). My main worry is with the stripping process. The recommended method is the melted solder thing where you tin and strip at the same time. But how do you know you have not tinned the enamel, since the whole thing is covered in solder? KI6AZS _______________________________________________ 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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You can see the enamel burn off, and the solder tin the copper.
Just make sure the iron is hot enough, and you take your time. 73 Stewart G3RXQ On Sun, 23 Oct 2005 01:36:58 -0700, Lee wrote: > I am still considering what my *grown up* rig will eventually be after I've > outlived my > > *first* rig . I always seem to go back to the K2 and that is where my head > and heart > are. But the devil keeps popping up, whispering in my ear that I'll never be > able to > strip and mount so many toroid coils (and that I'll probably zap an IC). > > My main worry is with the stripping process. The recommended method is the > melted solder thing where you tin and strip at the same time. But how do you > know > you have not tinned the enamel, since the whole thing is covered in solder? > > > KI6AZS > > _______________________________________________ > 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 |
RE: Neurotic about Toroids
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In reply to this post by Rockinghorse Winner
Hi,
This devil has many appearances and uses different names depending on the person in doubt. Several of the names are: Icom, Yeasu Kenwood, etc. It isn't that difficult. Put the part of the wire to be stripped flat on the surface of the edge of a table. Take a real sharp knife and scratch with an angle of 45 degrees (between the surface of the table and the blade of the knife) as you move the knife into the direction to the end of the wire. The coating will come off. Repeat this process several times when turning the wire around to make sure you don't press to hard on the knife. I did it this way, and none of the wires broke. If you do, there is plenty of spare wire to rewind the core. Success and have fun. Evert, PA2KW K2 : SN4836 -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Lee Sent: 23 October 2005 10:37 To: [hidden email] Subject: [Elecraft] Neurotic about Toroids I am still considering what my *grown up* rig will eventually be after I've outlived my *first* rig . I always seem to go back to the K2 and that is where my head and heart are. But the devil keeps popping up, whispering in my ear that I'll never be able to strip and mount so many toroid coils (and that I'll probably zap an IC). My main worry is with the stripping process. The recommended method is the melted solder thing where you tin and strip at the same time. But how do you know you have not tinned the enamel, since the whole thing is covered in solder? KI6AZS _______________________________________________ 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 Rockinghorse Winner
Lee,
Not to worry, the enamel itself will not adhere to the solder at all, so if you have the leads with a nice shiny tinned surface, you can know that they have been stripped as well. As for zapping ICs, practice safe ESD techniques at the workbench. If you have a wrist strap available, use it when handling ESD Sensitive devices, or even better, also use a properly grounded (through a high value resistance) anti-static mat on the workbench. At a minimum, follow the instructions in the manual to 'touch an unpainted metal surface' before handling these devices. The real key to safe ESD practice is to keep everything at the same potential - before handling ICs, I make sure everything is on my antistatic mat - that includes the circuit board, IC (still in its anti-static foam), any tools I will use, as well as both hands, and if I have any doubt or the air is particularly dry, I put the wrist strap on too. 73, Don W3FPR > -----Original Message----- > > My main worry is with the stripping process. The recommended > method is the > melted solder thing where you tin and strip at the same time. > But how do you know > you have not tinned the enamel, since the whole thing is covered > in solder? > _______________________________________________ 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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Hi Lee,
I had the same reservations, vis a vis, winding the toroids, and the advice you have received is spot on. There is an additional solution, however, and that is to purchase a complete set (for each kit) of pre-wound toroids. I went this direction and the product was absolutely first rate. I did check each one as I installed it, and they were uniformly outstanding. If you have the time and patience, wind them yourself, if either time or patience is a restricting resource, buy them. Here is the link: http://www.elecraft.com/Apps/ToroidGuy/toroidguy_prewound_toroids.htm As you can see from the link, elecraft endorses (that may not be the correct term for their relationship, but they at least provide the information to prospective buyers). Tom, W3QS -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Don Wilhelm Sent: Sunday, October 23, 2005 8:22 AM To: Lee; [hidden email] Subject: RE: [Elecraft] Neurotic about Toroids Lee, Not to worry, the enamel itself will not adhere to the solder at all, so if you have the leads with a nice shiny tinned surface, you can know that they have been stripped as well. As for zapping ICs, practice safe ESD techniques at the workbench. If you have a wrist strap available, use it when handling ESD Sensitive devices, or even better, also use a properly grounded (through a high value resistance) anti-static mat on the workbench. At a minimum, follow the instructions in the manual to 'touch an unpainted metal surface' before handling these devices. The real key to safe ESD practice is to keep everything at the same potential - before handling ICs, I make sure everything is on my antistatic mat - that includes the circuit board, IC (still in its anti-static foam), any tools I will use, as well as both hands, and if I have any doubt or the air is particularly dry, I put the wrist strap on too. 73, Don W3FPR > -----Original Message----- > > My main worry is with the stripping process. The recommended method > is the melted solder thing where you tin and strip at the same time. > But how do you know > you have not tinned the enamel, since the whole thing is covered in > solder? > _______________________________________________ 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 Rockinghorse Winner
Hi Lee:
At 03:36 AM 10/23/2005, you wrote: >I am still considering what my *grown up* rig will eventually be after >I've outlived my *first* rig. I always seem to go back to the K2 and that >is where my head and heart are. But the devil keeps popping up, >whispering in my ear that I'll never be able to strip and mount so many >toroid coils (and that I'll probably zap an IC). > >My main worry is with the stripping process. The recommended method is the >melted solder thing where you tin and strip at the same time. But how do >you know you have not tinned the enamel, since the whole thing is covered >in solder? Good question... easy answer... it's kinda like trying to 'wet down' an oily plate... the water refuses to stick to the plate because of the oil. Same for enameled wire... the enamel will not allow the solder to adhere to the copper beneath it! The solder just rolls off. Tinning a wire which is covered with HEAT-STRIPPABLE ENAMEL is not a difficult task... though it does take a bit of time... heat... and possibly a good technique. There are (generally) two types of insulating enamel... heat-strippable, and NON-heat-strippable (often referred to as FORMVAR-insulated wire). Formvar is in insulation VARnish which is very(!) resistant to heat and which you will generally have to scrape off the wire before it can be tinned. In general, most Formvar insulations are dark (often reddish-)brown in color. On the other hand, heat-strippable insulations are generally much lighter in color (golden or a clear red or green), and they will melt (and turn black), offering up the bare copper beneath the insulation, once the right amount of heat has been applied to them. From experience only, it appears that the 'right amount of heat' must be in the range of 700 deg to 800 deg F (370 deg to 425 deg C). You can remove the insulation in any of a number of ways. I'll discuss a few below: 1) SCRAPING it off with a (semi-)sharp blade. Hold the blade against the wire at right angles and pull the blade to the end of the wire, stripping off small strips of insulation with each pull. Repeat all the way around the wire, taking care to NOT NICK THE WIRE was you strip the insulation. The main problem I see with this method is that one can impart small nicks to the wire which may eventually result in weakening of the wire at the nick, especially if the wire is in a location where it may be subject to being flexed back and forth or in a connector which may be installed and removed frequently. The other possible problem with this method is that, if you are not careful in blade-stripping of the enamel, you will leave lengths of un-stripped enamel which can (if not burned away during the subsequent tinning process) result in a very poorly tinned wire. 2) SANDING it off with sandpaper, emery cloth, or some other similar abrasive medium. This method can work pretty well if you take the time to do it right. And it will not cause damage to the wire as a result of nicking with a blade. This method does often take some time to do properly and, like blade stripping, can result in 'blotchy' tinning if you don't apply enough heat once you tin the wire. 3) BURNING it off by use of a flame. This method seems to work pretty well but once you have successfully melted and burned the enamel, you still have to then clean away the blackened residue which still adheres to the wire itself. you CANNOT merely solder through the carbonized insulation. This method takes some time to accomplish properly, but it will generally result in a solderable wire. You DO have to use some care when using certain types of flame... the flame may be so hot, and uncontrolled, that you not only succeed in burning off the enamel but you also success in 'hardening' the copper to the point that it becomes brittle and will break much more easily once it is placed into use. 4) MELTING/BURNING it off by using the heat of molten solder. I tend to prefer this method, though some find it a bit more difficult to accomplish. The 'tricks' (if there are some) to this method are using a soldering iron which is hot enough, getting the melted solder TO the COPPER where it will quickly spread the heat, and being patient a bit patient. If you have a temp-controlled soldering iron, you'll want to set the tip temp up a bit higher than that which you use for normal soldering. I tend to use a tip temp of about 700 deg F (370 deg C) for soldering, but I bump that up to about 750 deg F (400 deg C) when I'm melting heat-strippable insulation. If you don't have a temp-controlled iron, chances are that your tip temp is already at or above the required temperature, so you probably won't have to worry about tip temperature. Additionally, a larger (width-wise) is recommended, though a fine tip will work. You want to melt a blob of solder into a clean iron tip, so it will be in good thermal contact with the tip of the iron and so the iron can continue to provide heat once the wire being stripped has been inserted into the 'blob' of solder. Heat transfers to the wire being stripped much more easily if it can come into contact with a point of BARE COPPER rather than if it is required to pass through the insulating enamel in order to get to the copper. As a result, once I have melted a small blob of solder onto the tip of my iron, I'll start the stripping process by inserting just the CUT end of the wire into the solder blob, allowing it to come into direct contact with the molten solder and to begin heating up the enamel. Within a few seconds of the bare copper touching the molten solder, I'll see some smoke and the enamel will begin to bubble up. At this point, I'll slowly insert more of the wire length into the solder blob, again waiting for the enamel to melt and burn away. I continue this until I have melted the enamel as far up on the length of the wire as needed, and then I slowly remove the wire from the solder blob by backing it out of the blob just as I had inserted it. Te end result is a tinned wire with a bit of 'dross' (burnt enamel) remaining at the upper end of the tinning and possibly a bit of burnt enamel on top of the tinner portion of the wire. I can now use my thumbnail to remove any races of remaining burnt enamel from the tinned wire. Finally, if you happen to have a heated vacuum-type desoldering tool, such as the Hakko 808, you can very easily strip your wires by merely applying a bit of solder to the nozzle of the stripper, then slowly inserting the cut end of the wire into the nozzle. Almost instantly, the enamel will start to melt and burn away, tinning the wire as it is inserted further into the nozzle. Then, once you have inserted the wire for enough to fully tin it, press the vacuum switch while you remove the wire from the nozzle. Almost too easy. Finally, when tinning toroidal inductor leads, try to tin them up just a bit PAST the edge of the toroidal core!!! Many builders stop tinning once they reach the bottom edge of the core. This all too often results in some unstripped wire being pulled down into the PC board hole once the toroidal inductor has been installed and its wires have been pulled taut in preparation for soldering. You do NOT want unstripped wire inside the plated-thru holes of the PC board. Doing so can result in poorly soldered joints which can (and will) fail at a crucial time. When I tin toroidal inductor leads, I'll bend them out at right angles from the body of the core, tin them almost all the way up to the body of the core, and then, once they're cool and cleaned, bend them back down against the body of the core. Of course, you don't want to risk having leads tinned in this manner shorting out against each other, but the way in which Elecraft has you winding your toroidal inductors, helps to ensure that the leads will remain well separated one from the other, so shorting between individual tinned leads should be a minor concern if they are installed into the right PC board holes and if they are then pulled taut before they are soldered. I see I've gone on much too long (again). So I'll stop here. But just realize that tinning heat-strippable wires is NOT difficult, and certainly not impossible, if you just use some care in the process. 73, Tom Hammond N0SS _______________________________________________ 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 Rockinghorse Winner
Lee,
After you've installed a toroid, check the resistance across the toroid leads (all pairs if it's a transformer) at the solder pads. If it's zero, you can be assured you stripped the leads properly and got a good solder joint on the board. Since I started doing that, I've never had a bad toroid installation. Take your time and enjoy building your K2. Elecraft and this excellent list are always there to back you up, so you CAN'T fail. 72, Bruce N7CEE K2 #244 _______________________________________________ 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: Neurotic about Toroids
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In reply to this post by Stewart Baker
KI6AZS wrote:
But how do you know you have not tinned the enamel, since the whole thing is covered in solder? ---------------------------- Use you ohmmeter to confirm continuity from one end to the other. The biggest mistake most builders make tinning the toroid leads is that they fail to tin them close enough to the body of the toroid. You need to tin right up to the core! Unwrap a part of a turn so you can tin he wire without burning the adjacent turns, then reposition it so the solder starts where the wire leaves the side of the core. When the wire isn't tinned up high enough, it's easy to pull the tinned section all the way through the board so you're trying to solder to the un-tinned wire above where you stripped it! Also, it is NOT necessary to pull down hard on the leads when mounting the toroids. Just pull all the excess lead through the hole, so the toroid is sitting or standing as indicated against the board. As a final check BEFORE soldering, look to see if tinned wire is visible at the edge of the pad on the toroid side. IF you see enameled, un-tinned wire going into the PCB hole, you didn't tin it far enough up. Remove the toroid and tin the lead closer to the core. It's really harder to describe than to do, but some ops find it simply not much fun to wind and tin toroids. That's why the "toroidguy" is around. You should have found a flyer in your kit box advertising his services. You can also find his info under Builder's Resources on www.elecraft.com. He'll send you a set of pre-wound, pre-tinned toroids all ready to drop in to your kit if you want. About the I.C. concerns, simply following the grounding procedures given in the book and you'll be fine! The big issue, if you aren't wearing a ground strap, is to touch something unpainted and GROUNDED before picking up an I.C., and touch it AGAIN regularly, especially after getting up or squirming around in your seat. A little clothes-to-vinyl or cloth friction on the seat can quickly produce a static charge. If you aren't sure about the ground, the mains ground is FB, if it is grounded. A cheap tester from your hardware store can confirm whether your mains ground circuit is properly hooked up. 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 |
Re: Neurotic about Toroids
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In reply to this post by Rockinghorse Winner
Lee,
If you don't choose to buy Mychael's pre-wound toroids (which I did for the K2 RF board) you might want also to try these two hints: 1. Make sure to wind the toroid the right way, with the top wire being on the correct left/right side of the bottom wire. Elecraft's manuals always have pictures to go by. If you get it backwards, it will be a mirror image of what it is supposed to be, and it won't fit in the hole right, and no amount of turning the toroid around again will make the holes line up, hi hi. 2. Everybody tells you to count the times the wire goes through the hole, but nobody tells you how to verify it afterwards! Once you're done, count the number of turns on the inside rim of the toroid and ignore the outside rim. 73, Leigh / WA5ZNU _______________________________________________ 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: Neurotic about Toroids
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In reply to this post by Evert Bakker (PA2KW)
----- Original Message --------------- Subject: RE: [Elecraft] Neurotic about Toroids From: "Evert Bakker (PA2KW)" <[hidden email]> Date: Sun, 23 Oct 2005 11:17:01 +0200 To: "'Lee'" <[hidden email]> Cc: "Elecraft e-mail reflector" <[hidden email]> > >It isn't that difficult. >Put the part of the wire to be stripped flat on the surface of the edge of a >table. Take a real sharp knife and scratch with an angle of 45 degrees >(between the surface of the table and the blade of the knife) as you move >the knife into the direction to the end of the wire. The coating will come >off. Repeat this process several times when turning the wire around to make >sure you don't press to hard on the knife. > >I did it this way, and none of the wires broke. If you do, there is plenty >of spare wire to rewind the core. >Success and have fun. > >Evert, PA2KW >K2 : SN4836 >Elecraft web page: http://www.elecraft.com Thank you for backing me up. That's how I did it on my Ten Tec QRP kit, and it worked out ok. I guess I put too much into the prevailing view on the reflector that the *solder method* is the best. There's always more than one way to do something, and if it gets the job done, why not? I will probably try both ways at the start just to be familiar with them, and then make my decision on which method to use. There doesn't seem to be much choice in rigs. The Japanese rigs don't seem to offer quiet refined receivers for less than 2 G's. I mean the boxes are built to very close tolerances, and the dials, buttons and what not have a refined look and feel to them, but, really, who cares? I guess my dream station would be an Elecraft K2/100 with Argonaut V as backup rig. Wow! Lee KI6AZS _______________________________________________ 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 |
The Changing World of Radio
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In reply to this post by Leigh L. Klotz Jr WA5ZNU
While it's great to see continued, even growing, interest in CW on the Ham
bands, and the efforts of folks like the Maritime Historical Radio society maintaining historic commercial stations like KPH for special events*, there is the occasional reminder that our world is changing. Richard "Dick" Dillman, W6AWO, QSP this message from the Italian station IAR on another reflector. I thought the CW buffs here would appreciate seeing it. Imagine, if you will, a strong, clean CW note with these words: CQ CQ CQ DE IAR IAR THIS IS THE FINAL TRANSMISSION FROM ROMA RADIO MORSE SERVICE. WE CONCLUDE OUR WATCHKEEPING AFTER MANY YEARS OF CONTINUOUS SERVICE WITH PRIDE AND SADNESS ON OCTOBER THE 31ST. TELECOM ITALIA COAST STATIONS WISHES ALL SEAFARERS FAIR WINDS AND FOLLOWING SEAS. WE SALUTE ALL WHO HAVE SERVED OUR PROFESSION WITH SKILL AND DEDICATION THROUGH THE YEARS. = DE IAR IAR AR VA The commercial stations are going silent because it's good business to use other modes and technologies. We Hams are not driven by such mundane considerations. We continue to pound brass simply because it interests us. I don't believe there can be any better reason than that. Ron AC7AC * http://www.radiomarine.org/kph-proj.html _______________________________________________ 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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