+++++++++++++++++++++++++++++++++++++++++++++++++++ Note: See also Gary_Ss_Build_Tips +++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Mon, 02 Apr 2001 11:11:49 -0500 From: Tom Hammond =?iso-8859-1?Q?N=D8SS?= Subject: Re: [Elecraft] Scraping wires for toroids Art: >What's the best method of scraping the varnish (or whatever that stuff is >that makes the wire "colored") from the end of toroid wires? If anyone says >sandpaper, what grit do you use? Probably the one of the BEST ways to do it is to NOT bother with any scraping at all... use the SOLDER BLOB method: 1) Cut the toroidal inductor lead to about 1/2" LONGER than you think you'll need it to be. 2) Using a nice HOT iron (>725 degrees F, if possible), melt a moderate size blob of solder on the tip of the iron. 3) Place the CUT END of the wire INTO the solder blob and allow it to heat up to the point that you can see the heat-strippable enamel starting to smoke and bubble a bit. This usually takes 3-4 seconds. 4) Once the enamel is smokin' and bubblin', slowly insert more of the wire into the solder blob, a little at a time, and allow it to heat and burn off the wire. 5) When you get to the point that you have burned off the enamel almost all the way to the winding themselves, remove the wire, allow it to cool and then take a fingernail and scrape off any remaining burned enamel residue. The result should be a nicely tinned lead. NOTE: It will usually help if you can add a bit of solder AS you continue to hear/burn the enamel from the wire. The added flux makes things go faster. I usually try to 'form' the solder, as it comes off the roll, into a "question mark" (kinda) so that the end of the solder is off the table top and pointing downward a bit. Then I hold the toroid BY ITS BACK SIDE, to keep fingers as far from the heated turns as possible, and place the lead against the tip of the iron. I then can move the iron AND wire up TO the solder, so I can easily apply additional solder as required. You can also HOLD the core in a fixed position and move the iron and solder TO it. Just don't hold the core in something that might break it. Heat travels fastest thru the wire once it finds BARE COPPER, so that's why I suggest placing the CUT END into the solder blob first. In this way, the solder will find the bare, cut end immediately, and the heat will travel more quickly than if you merely laid the length of the enamel-covered wire into the solder blob, where the heat would have to travel thru the enamel first. There are NUMEROUS other ways to tin toroidal inductor leads. Each of us has his 'preferred' method. Try several (you'll have the opportunity to do so ) and then PICK ONE and make it yours. 73 - Tom Hammond N0SS ++++++++++++++++++++++++++++++++++++++ Date: Mon, 2 Apr 2001 12:57:04 EDT From: LHLOUSEK at aol.com Subject: Re: [Elecraft] Scraping wires for toroids Hi Art, Winding toroids and stripping the magnet wire is a highly personal thing. The best thing is to try various method and see which you like the best. I tried various solder blobs at different iron temps, sand paper and scraping with a single edge hardware razor blade. I like the razor blade method the best. Fast, clean and efficient as long as you don't nick the wire. You need a hardwood board or piece of aluminum to lay the wire on while scraping. Three or four scrapes does it nicely. Remove any remaining insulation residue (chad?) while tinning the wire prior to soldering it into the board. Luigi W7DZN +++++++++++++++++++++++++++++++++++++ On a personal note, I used the razor blade method and it worked just fine for me.... Doug, VE3MCF +++++++++++++++++++++++++++++++++++++++++ Date: Mon, 02 Apr 2001 12:02:06 -0500 From: "Timothy A. Raymer" Subject: Re: [Elecraft] Scraping wires for toroids Arthur, I have had good luck with the "scraping" technique described by one of our fellow listees. Since I can't find the original e-mail or remember his call, I will refer to him simply as, "The Exalted Scraper." (As an aside; "Exalted Scraper", congratulations on your promotion!) Make a reference mark on the wire. I use a fine point sharpie. Start from the line with a sharp bladed pocket knife. It seems to work better with a pocket knife with a thicker and less flexible blade. I use the tip for better control. Tilt the top of the blade towards you. Gently scrape down the end of the wire. This tilt of the edge of the blade allows for the enamel to be scraped with less chance of nicking the wire or the scraper's finger. repeat all the way around the wire. I had poor lick with the blob technique because my Weller Iron has a 700°F tip, and I do not have enough patience to change it repeatedly. Two other things I found handy were: Do the first lead of the wire to be wound BEFORE you wind the torroid. Worked better for me. Your mileage may vary. Scrape the wires under your illuminated magnifying glass. Do ALL the soldering work on your K2 under your illuminated magnifying glass. It makes for easy seeing, and less mistakes. You have the added benefit of a glass lens between you and the solder. If you have an adjustable temperature iron, you may want to try the blob technique first. If you are intimate with a good pocket knife, scrape away! As Tom said, try several, use the one that works best for you. Good luck! Tim Raymer 73 de KA0OUV ++++++++++++++++++++++++++++++++++++++++++ Date: Mon, 02 Apr 2001 16:44:06 -0700 From: "Steve Giltinan" Subject: [Elecraft] re:toroid wire scraping My method for enamel removal is as follows. I first wined the toroid,then gently place it in a small vice. I then place the vice under a lit magnifying lamp. After cutting the leads to about a half inch from the core,I use a butane lighter to burn the enamel back toward the core, stopping about 1/8 inch from the core.Under the mag. glass you can follow the enamel blistering as the heat moves up the wire.Pull the flame away as you approach your stopping point. I then use an exacto knife to gently scrape away the burned enamel. I take a minute or two to do each wire. This method has worked great for me, hope it will be of help to a new builder. Good Luck, AC7KL Steve ++++++++++++++++++++++++++++++++++++++ Date: Tue, 3 Apr 2001 08:43:44 +0200 From: "Dieter Klaschka" Subject: Re: [Elecraft] Scraping wires for toroids - ----- Original Message ----- From: "Arthur Laurent" To: Sent: Monday, April 02, 2001 5:19 PM Subject: [Elecraft] Scraping wires for toroids > What's the best method of scraping the varnish (or whatever that stuff is > that makes the wire "colored") from the end of toroid wires? If anyone says > sandpaper, what grit do you use? > > Thanks for any good ideas -- and even for the bad ones! > > 73 de KD4CSO > Art (K2 #1963 a-building) Hi, Arthur, You will find different methods when you search the archives here. You may take one for granted: don't use a knife. When you have wound the wires on the toroid so that there is rather low space left a 60 watt (or even more!) iron with a 'blub' of solder tin will do the job; the varnish will 'melt'. I personally used a kind of de-isolating pliers (look like two front teeth in the mouth) which I scrapped the varnish off the wires. The advantage is that you come exactly near the core; but it requires a certain kind of moderate pressure you will get by experience. It's more a caress of the wire than a scrapping. But that's what little K1 needs anyway. Not to mention it's mojo, hi. I did not use sand-paper : difficult handling to fold it, hold the tiny core and scrap... 72, Dieter.DL2BQD K1 378 +++++++++++++++++++++++++++++++++++++++ Date: Tue, 03 Apr 2001 10:06:29 +0100 From: "J. Ellis" Subject: Re: [Elecraft] Scraping wires for toroids Arthur Laurent wrote: > What's the best method of scraping the varnish -- Art, I like to use one of these butane "mini torches". They are made by a number of companies, they're cheap and HOT! Once I burn the amount of enamel off, I just take some very fine grit sandpaper to remove the residue. Incidentally, the little butane torch is great for heating up the shield part of a PL-259 before you actually take the iron to it. Gets it real hot, real quick so you spend less time with the iron. Just my $0.02, FWIW YMMV etc. :-) Jeanette & John Ellis (NP2C & NP2B) P.O. Box 24492, Christiansted, St. Croix U.S. Virgin Islands 00824-0492 tel (340) 773-9643, fax (340) 773-6574 website http://www.viaccess.net/~jellis When responding to e-mail, please send to jeanette at atthehelm.com or john at atthehelm.com ++++++++++++++++++++++++++++++++++++++++++++ Date: Tue, 03 Apr 2001 07:16:53 -0500 From: Tom Hammond =?iso-8859-1?Q?N=D8SS?= Subject: RE: [Elecraft] Scraping wires for toroids Hi Vic: >Does this (the "solder blob" method) work for all enamel wire, or is the >Elecraft stuff special ? It doesn't work on ALL enameled wires, but on ALL HEAT-STRIPPABLE enameled wires! There's a type of enamel insulation, commonly known as FORMVAR. It's generally a VERY dark red... maybe even dark reddish brown, which is virtually impervious to heat!!! It's specifically designed for use in places where the heat may be really high. You'll find it on most high-power RF chokes (plate chokes, hi-current filament chokes, commercially made baluns, etc.). This stuff HAS to be SCRAPED off. The heat-strippable enamels are usually a much more 'transparent' color, usually a clear red, green, or amber color. I think that almost all of the solid copper wires (other than antenna wire and vinyl-insulated) available at Radio Shack are heat-strippable. Belden uses the trade name ThermalEze (if I recall) for most of its heat-strippable wires, and there are others available from other manufacturers. When in question, I always TEST the wire first, to see if it's heat-strippable. If it is, I use the solder blob technique. If not, I then LIGHTLY scrape the enamel off with a single-edged razor blade or a knife blade held at a 90-degree angle to the wire. >I have been scraping the enamel off with a hobby knife for years and >usually end up cutting or roughing up my fingers ! I don't think I've ever cut my fingers when scraping, even when using a single-edged razor blade... mainly because I always (try to) lay the wire on a flat surface, rather than a finger, and then scrape against the top edge of the wire. As noted by several other commentors, I've often found that I nicked the wire as I scraped away at it. And just about ANY time you nick a wire, you're dooming it to break somewhere along the line. >This sounds infinately better. Again, it's all what you are used to using, and what you 'make your own'. I suspect that any of the methods suggested will work well for some of us... but not necessarily for ALL of us though. Maybe a year ago, one commentor, writing on using the solder blob method, noted that he found that the enamel melted MUCH more quickly if he took at least one pass over the enamel with a knife blade... to 'break' the contiguity of the enamel covering and to expose bare copper directly to the solder (remember the wire heats MUCH more rapidly if you get the solder to bare copper). Taking a single pass with the knife does often help, but I've been able to obtain quite good results by merely sticking the clipped end of the wire into the blob, so the (tiny) bare end is heated first. Once the melting process begins, it will progress pretty quickly as long as you add just a bit more solder (and thus more rosin) to the blob as you go. A 700 F (371 C) or hotter iron work best. WARNING - Experience dictates that you perform this activity OVER THE DESK and NOT over your lap! Been there, WON'T do THAT (ever) again! 73 - Tom Hammond N0SS ++++++++++++++++++++++++++++++++++++++++++++++ Date: Wed, 4 Apr 2001 19:26:04 -0700 From: "Stuart Barney, Jr." Subject: [Elecraft] K2 - T7 (snipped) An aside, I finally was able to get the 'solder blob' method of tinning the leads to work when I switched from Kester No Clean to Kester "44". Works like a champ now. Sure beats burning and sanding. 73, Stu KD7LCG +++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++ Date: Thu, 23 Aug 2001 14:27:07 -0700 From: "Ron D' Eau Claire" Subject: RE: [Elecraft] Toroid wire stripping... One thing that I've noticed when heat-stripping enamel wire is to be sure to get the cut end of the wire into the molten solder. It strips much faster and with less heat if the exposed end of the wire gets wetted by the solder. It appears that the flux or solder or both wick up under the enamel from the end, causing it to separate from the wire much more quickly than if the enamel is simply heated until it 'burns through'. Ron AC7AC K2 # 1289 +++++++++++++++++++++++++ Date: Wed, 05 Sep 2001 14:30:31 -0600 From: John Subject: [Elecraft] toroid leads Perhaps this has been mentioned before. To tin the leads, I put the handle of the iron under the soldering station to hold it in place, tip extended over the edge of the work area. Use a book or something heavy if no soldering station. This leaves both hands free, one to apply solder blob to the iron tip (and more solder if required), the other hand to hold the toroid. Then drag the lead through the blob, starting at the toroid end if the lead. When you get to the end of the lead, a little downward pressure (spring action}, gets rid of excess solder. Try it a few times with left over enamel wire. It has worked wonders for me, almost look forward to winding more. John, k7up K1 637, K2 2012, K2 2223 (still in the box ++++++++++++++++++++++++ Date: Wed, 05 Sep 2001 16:38:30 -0400 From: Stark W Craddock Subject: [Elecraft] Toroid wire stripping... Hello Elecraft fans, It is easy to strip the enamel from the wire (after the toroid is wound) by using an Unger soldering iron that has a screw in tip .. except don't screw in the tip. Heat tne iron and hold the element vertical, then fill the opening where the tip was to be with solder. This is like a 'one wire solder pot'. Tins the wire while removing the enamel with ease. Takes all the 'work' out of stripping the wires. Bill Craddock WB4NHC ++++++++++++++++++++++++ Date: Sat, 29 Sep 2001 14:24:59 -0400 From: Jim Campbell Subject: [Elecraft] Broken Toroid - Summary Thanks to all for the prompt, helpful replies to my question both on the list and directly to me. I learned a number of things. First, you can use super-glue or the like to glue the toroid back together and it will probably work just fine. I've glued the toroid back together and will continue with the assembly of the K2. However, since it is used in the VFO circuit, I will replace it in due time. I would always wonder if it was the cause of any unusual behavior by the K2. Also, I want my K2 to be the best it can be. Second, thanks to Tom Hammond, N0SS, I learned how to strip the magnet wire properly with a soldering iron. I quote from Tom's instructions: "Get your iron hot, melt a blob of fresh solder on the tip of the iron. Insert the CUT END of the wire into the solder blob and wait 3-4 seconds, until the enamel begins to smoke and bubble. Then add a bit more solder (for the rosin, not for the solder itself) and slowly insert more of the wire, until you have the required length of wire stripped and tinned. Withdraw the wire in the same manner as you inserted it. The result should be a fully-tinned lead with only a small amount of burnt enamel residue on it. Take your thumbnail and pull the lead across it to scrape away any remaining residue." I wish I had known this earlier. I did use a soldering iron, but apparently didn't use the proper technique. I was using sandpaper to complete the job when I broke the toroid. Third, toroids are available in lots of places. From where I live (Raleigh, NC) delivery time can be problematic. I chose to go with Radio Shack online. Four of these toroids plus shipping is less than $8 and delivery in less than a week. Another ham offered to send me one, but he is on the west coast. My mail from the west coast is taking well over a week these days. Last, I learned how fast and helpful this list is in responding to problems. I'm looking forward to meeting many of you on the air in the coming weeks and months. Thanks again, 72 and 73, Jim W4BQP ++++++++++++++++++ Date: Mon, 8 Oct 2001 18:09:31 +0100 From: "Raven, Timothy" Subject: [Elecraft] Tinning Those Torroids Leads I Have found a great way to do this. Take an old Antex big soldering iron bit, and saw off the tip. With the remaining part, drill a hole down into the copper up to about 5mm in depth, so that the drill does not break through to where the heating element goes. I found a 1/8 inch drill was about right, but that's not critical as long as it in a smaller diameter than the remaining Antex bit. Place the handle of the soldering iron in a vice, so that the bit, with a hole in it is pointing up in the air. Switch on and fill the hole that you have drilled out with solder .You have then created a mini solder pot. I found that if I just dipped the enamel wire in and out, it stripped the enamel, and tinned the lead in less than a second. I suggest you do this in a well ventilated room. 73 Tim G4ARI. ++++++++++++++++ Date: Sat, 15 Dec 2001 09:27:11 -0000 From: "Paul Barlow" Subject: [Elecraft] RE: PTTL Hello Elecrafters, this is a non-orthodox tinning toroid statement. I was initiated into the great mysteries of toroid winding when I built a Sierra and a few band cards, if you think the K2 has a lot of toroids, well build a Sierra and see! I use a crochet hook to pull the wire through, it makes for nice tight toroids and the wire doesn't kink. I don't know wht a crochet hook is in American if it isn't a crochet hook). I always scrape the insulatin off the wire with a sharp knife, with the wire flat on my thumb; I've always had good toroids that way, or at least so far so good. It may be that my iron isn't hot enough to strip the enamel properly on teh wire supplied with the K2 (it's a very ordinary Antex brand 18W iron with a large thermal mass around teh element and a small chisel bit). I did try the prescribed method but it just took too long. The only PTTL propblem I had was when I tried this method as directed when building a WM20 (yes we have a kit building probelem here I know) which took a lot of head scratching from a better electronic technician than I am to sort out. This is just my 2p / £0.02 worth. I now wind toroids for pleasure, well not really, but I will rewind one if I don't think it'e neat enough. I alos believe that you do have to learn to wind them yourself, it is part of the fun, (if that's what you call it). 72/73 Paul M0CDP GQRP 10289 Fists 5579 K2 #2356 KNB2 KAF2 +++++++++++++++++ Date: Sat, 15 Dec 2001 09:40:50 -0800 From: lhlousek Subject: Re: [Elecraft] RE: PTTL I've never had much luck with the heat strip method. It generates a lot of smoke and leaves the toroid leads encrusted with dross. I found scraping and tinning to be quicker, neater, and more reliable. People have expressed concern about nicking the wire. With reasonable techique I believe it is pretty unlikely to nick the wire. I've done a bunch (many more than in my K1 and K2), checked a few under a microscope, and have had no nicking problems. I wonder if Gary has had to fix many customer boards that had problems due to nicked toroids wires. Lou W7DZN +++++++++++++++++++ Date: Sun, 23 Dec 2001 11:30:05 EST From: DolfinDon at aol.com Subject: [Elecraft] Winding Toroids Hi All Here are a few techniques I have discovered winding toroids. 1) This works for right handed (you lefties will have to reverse it ;). Hold the core in your left hand between your thumb and index finger. Pass the precut length of wire through the core leaving about 1 inch on the bottom and the long end on top. This counts as the first turn. Pinch the wire on the bottom between the core and your index finger. Bring the long end around to the bottom and pass through the core. This counts as the second turn. Continue adding turns filling the core in a counter clockwise direction. With three turns on the core the wire will not slip, you can pull the turns tighter and not have to hold the short end as you rotate the core to fill. Just before pulling the wire tight, adjust the position on the core with your thumb as a guide. Continue this motion until you have the required number of turns. Flip the core over and the winding should match the picture in the manual. I find this underhand winding motion is more natural, the wire does not kink and I can pull the turns tighter. 2) When winding on the ferrite cores don't pull the wire through the core. Feed the wire with your finger until the turn is almost down on the core then pull tight. The ferrite cores have a sharp edge on the inside and pulling the wire against it will scrape the enamel. 3) When counting turns on a finished torroid count the number of turns on the outside of the core and add one for the correct count. 4) When winding the transformers leave a couple of inches of wire at the start of the second winding and spread the turns of the first winding out so the second winding can fit between. After completing the second winding if it is not centered on the core you can use the extra wire to add a turn on one end and remove a turn on the other end so the winding is centered, but keeping the same number of turns. 5) Gary has covered wire stripping so I don't need to go over that again. When mounting the torroid I pull the wire tight so the core is down against the board and then bend the wire parallel to the board. Look carefully at the wire on the bottom of board (use a magnifier) and look for any colored enamel. If the enamel is visible, remove the torroid and strip a little more of the insulation. If everything looks good solder. 6) Spend a little time adjusting the turns on the core so they are evenly spaced and cover 80 - 90% of the core. Pick one side and wind all the torroids with that side up. Red side up for instance that way just like installing all of the resistors the same direction the radio will look better. When you are showing off your new radio all of those neatly wound torroids are the first thing most people notice. When you tell them you wound them all yourself, then they are really impressed. We won't tell them how easy they are to make ;) Using the above technique I can wind and strip a complete set of K2 torroids in about an hour and a half, you can too. Don Brown KD5NDB K1 #1000 K1 #542 all opt K2 #1808 all opt K2 #2174 K2 #2153 ++++++++++++++++ From: "Don Brown" To: "Elecraft" Date: Sun, 30 Jun 2002 08:42:48 -0500 Subject: [Elecraft] Absolutely positively the BEST way to strip toroid leads Hi Gang I stumbled across the best way to strip toroid leads I have found, and I = have tried them all. I had been using the solder blob method but I still = could not get the leads as clean as I would like. I also tried a solder p= ot but it is hard to get the leads far enough into the pot without cookin= g the toroid and you still end up with too much solder on the leads makin= g it difficult to insert into the holes on the board. =20 I had taken a break from building a KPA100 and when I came back to it my = WES-50 soldering station had turned itself off. While it was reheating I = picked my Hakko desoldering gun and slipped the toroid lead up into the n= ozzle and applied a little solder. After about 10 seconds I hit the sucti= on switch and removed the torroid lead. I was amazed the lead was perfect= ly clean with just the slightest coating of solder right up to the core. = There was no black residue, no excess solder and no damage to the core or= windings. I did this on several more toroids and it works every time and= it is fast. I can wind, strip and install a toroid in 1 to 2 minutes usi= ng this method. Clip the leads to about 3/4 to 1 in before you insert the= m into the desoldering station nozzle and run the nozzle right up next to= the core. Apply a little solder wait a few seconds, suck the excess sold= er off and remove the lead. I am not telling you to go out and buy a desoldering station just to stri= p toriods. But if you already have one this is the best way to do the job= . The inexpensive desoldering irons with the rubber bulb may work as well= (I have never had much luck with them desoldering, not enough suck) Try it I think you will like it Don Brown KD5NDB 4 K2's 4 K1's all options several times 2 KPA100's +++++++++++++++++ From: "Don Brown" To: , Subject: Re: [Elecraft] K1 Construction. Preparing Toroid Wires and soldering techniques. Date: Fri, 4 Apr 2003 07:30:42 -0600 Hi It seems like you are making it too hard. The tinning process you are doing is almost what is required to do the heat striping. The problem with scraping and/or sanding is the risk of nicking the wire. Here a few tricks for heat striping. After winding the toroid cut the leads to about 3/4 inch. The enamel acts as a heat insulator so it is hard to get the striping started up next the the toroid so start at the clipped end of the wire. Place your iron on the end of the wire and apply a good amount of solder forming a blob. The heat will start to flow up the wire and the enamel will begin to bubble up just in front of the blob. As the enamel burns off keep moving closer to the toroid and keep adding more solder. You must add more solder to keep a good amount of flux in the blob. If the blob is not bright and is not smoking you need more solder. The flux is what helps clean the lead. Keep a piece of cardboard under the toroid so the excess solder that drips from the blob will not burn your bench. Stop when the blob is just touching the core. You should have a clean stripped and tinned lead right up to the core. When installing the toroid insert the wires into the holes. Pull the wires tight from the back side with needle nose pliers and bend the wires sideways against the board to hold the toroid tight while you solder. The joint should be bright with a good filet around the lead. You can also use a heated solder sucker type iron (like a Hakko 808) to strip the wires. Just insert the lead into the nozzle, add some solder, wait a sew seconds and pull the trigger. Hope this helps Don Brown KD5NDB 11 K2's and counting (#12 in work now) 3 K1's 5 KPA100 2 KAT100 all options many times ----- Original Message ----- From: To: Sent: Friday, April 04, 2003 4:21 AM Subject: [Elecraft] K1 Construction. Preparing Toroid Wires and soldering techniques. > Greetings guys. I've just completed construction of the KFL1-4 filter board > for my K1 and just thought I would share a few thoughts on toroid leads. I > know the elecraft approved method is heat stripping, but I didn't have much > joy with this method myself, so I fell back on my normal tedious method of > scraping the enamel off. I used the edge of a small (1" dia) model makers > abrasive wheel but any other abrasive tool would do. It's a bit fiddley and > you need to keep rotating the wire to make sure you have all the enamel > off, (wire must not be damaged ie knicked) but it does the trick. When > tinning I used a nice hot iron and applied small amounts of solder 2 or 3 > times. I find that if you try to tin the whole lead with one application of > solder, the flux burns away too fast and it only "takes" on part of the > lead and you end up with a blob of useless old solder hanging off it. > Better to use a very small ammount of solder and tin a small part (say > 1/4") at a time and using fresh solder each time. When tinned, you can use > light abrasion to gently scrape off any tiny black dots of burnt flux. I > also applied IPA is a degreasant before tinning (but maybe didn't need to). > Anyhow I found that this works for me, the leads all soldered straight away > to the PCB. > > I think lots of beginners don't realise that once fresh solder has melted > it must be run and in place within 3 secs prefferably less, any longer and > you need fresh solder. The flux only does it's job for a few seconds if > that. eg if the solder doesn't take/run immediately it is applied, then > remove iron, clean wires/pad of old flux and repeat with clean tip and new > solder, don't fiddle about with it, quit and start again. Hope this helps. > Soldering is a bit of an art and we all do it differently, you've just got > to find what works for you. ++++++++++++++++++++ From: "Brian Machesney" To: Date: Fri, 4 Apr 2003 09:23:19 -0500 Subject: [Elecraft] re: Preparing Toroid Wires I have a quick method that has worked well for me. It's a variation on a theme described in the Elecraft manuals. I use a quick flash from a miniature butane torch, the kind you can sometimes find being sold as a high-powered cigar lighter. I operate the torch at minimum power for this application, more power when I'm lighting a cigar outside to keep the bugs off on Field Day! After trimming the lead to about 3/4", I ignite the torch and start melting the enamel about 1/4" from the toroid, moving quickly toward the end of the wire. I know I'm done when I see the "flash" of the melting enamel as it runs out of wire! A few gentle passes with the blunt side of an exacto knife blade and, voila! No tinning problems or related issues to date, with a K1, K2 with many options, KPA100 and KAT150 under my belt. Brian K1LI K2 #3070, K1 #270 +++++++++++++++++