+++++++++++++++++ See also Gary S's Build Tips +++++++++++++++++ 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 +++++++++++++++++ Date: Sun, 23 Dec 2001 10:50:31 -0800 From: lhlousek Subject: Re: [Elecraft] Winding Toroids <>> One trick for toriods with many turns is to pass only 1/2 the wire through the core, wind 1/2 the number of turns, then flip the core over and wind the second 1/2 of the turns exactly like you wound the first 1/2. This way you only have to thread 1/2 the length of the wire as you wind. Lou W7DZN +++++++++++++++++ Date: Sun, 23 Dec 2001 18:41:58 -0500 From: Charles Greene Subject: Re: [Elecraft] Winding Toroids At 10:50 AM 12/23/2001 -0800, lhlousek wrote: ><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. ...>>> > >One trick for toriods with many turns is to pass only 1/2 the wire through the >core, wind 1/2 the number of turns, then flip the core over and wind the >second >1/2 of the turns exactly like you wound the first 1/2. This way you only have >to thread 1/2 the length of the wire as you wind. I always clamp the toroid in a vise. That way you have two hands to work the wire. Use an old dish towel over the jaws of the vise to keep from marring the toroid or the wire. Pull each winding tight and flatten the wire against the top. on each turn. Happy Holidays and Toroid winding! 73, Chas, W1CG ++++++++++++++++ Date: Sun, 23 Dec 2001 22:23:09 -0500 From: "Don Wilhelm" Subject: Re: [Elecraft] Winding Toroids Gang, The method of winding 1/2 the total number of turns works FB for me too, but I have found it is really easy to end up with an extra turn that is created in the 'flipping' process - check carefully please. 73, Don W3FPR - ----- Original Message ----- > > One trick for toriods with many turns is to pass only 1/2 the wire through the > core, wind 1/2 the number of turns, then flip the core over and wind the second > 1/2 of the turns exactly like you wound the first 1/2. This way you only have > to thread 1/2 the length of the wire as you wind. > +++++++++++++++++ Date: Mon, 24 Dec 2001 06:21:44 -0600 From: Tom Hammond =?iso-8859-1?Q?N=D8SS?= Subject: Re: [Elecraft] Winding Toroids >W3FPR wrote: >The method of winding 1/2 the total number of turns works FB for me too, but >I have found it is really easy to end up with an extra turn that is created >in the 'flipping' process - check carefully please. I've been using this method for years... initially, I had this problem, but then I 'educated' myself to always remember to count the first time I 'hung' the loop of wire on the core as TURN #1. After that, I've never had a problem. Regardless, you whould ALWAYS COUNT TURNS WHEN YOU ARE FINISHED WINDING _BEFORE_ you put the toroidal inductor down on the bench. Tom N0SS +++++++++++++++++++ Date: Mon, 24 Dec 2001 07:46:06 -0800 From: Jerry Kincade Subject: Re: [Elecraft] Winding Toroids If you want to measure your toroid's inductance to a gnat's eyebrow (as well as small capacitors), check out the L/C Meter IIB at http://www.aade.com/ . This thing is small, simple and fast to use, works perfectly, and is very accurate. It's also a $99 easy to build kit vs. $300 and up (way up!) for the fancy HP and B&K "storebought" versions. Probably the best bang for the workbench buck ever. It is interesting and informative to see exactly how much inductance (to a hundredth of a uH) you are removing or adding with each turn, and the effect of changing core mixes and wire sizes. It's also great for sorting out and testing big boatanchor air and vacuum caps and inductors. With it's test lead capacitance zeroing function, its the only affordable meter I know of that will accurately measure very small capacitors, even down in the single digit pf range. No financial connection with Neal, but he's one of us - like Elecraft, he makes good stuff and backs it up 100%. 73, Jerry W5KP ++++++++++++++++++ Date: Mon, 24 Dec 2001 09:47:00 -0500 From: "David A. Belsley" Subject: Re: [Elecraft] Winding Toroids I'll second Jerry's enthusiasm for the L/C Meter IIB. I won't go so far as to say, "I don't know how I got along without it," because, without it, I didn't get along. That's why I got it. best wishes, dave belsley, w1euy +++++++++++++++++ Date: Mon, 24 Dec 2001 09:32:36 -0600 From: "Alva Anderson W5VCJ" Subject: Re: [Elecraft] Winding Toroids I developed a trick since I was constantly getting interrupted, or I'd just go brain dead. This should work either way you wind (all or half-flip). I mark every 5th turn with felt tip permanent marker AS I AM WINDING. This way, even if I lose track or get interrupted, I have the marks there to begin again. It also helps when you are finished winding and go back for the double check to make sure it has the correct number of turns. ++++++++++++++++++ From: "Kempter, Bob" To: "Elecraft Reflector (E-mail)" Date: Mon, 4 Mar 2002 14:58:54 -0800 Subject: [Elecraft] Toroid winding idea. Hi All: I finished my K2 over the weekend, to the basic CW rig level, and it is doing just fine. I want to share a way of winding toroids that I found in the ARRL book _QRP Power!_. It is in a sidebar that relates to winding toroids with a paperclip to hook and pull the wire through the toroid. After learning this one, I was amazed at how much faster, easier, and with no kinks in the wire this method provides. I thought this method of winding toroids was well known, but searching the Net resulted in no other references. I followed their directions with pictures and here is how I now wind toroids: First, prepare a metal paperclip by finding a small one, standard office size is fine. Bend it out by straightening the bend between the big bend and the small bend. With pliers, make the small bend smaller, but no less than 5 times the diameter of the wire you are pulling. Mine is 1/8 inch or slightly less. I have used 1/16, but it binds a bit. I trimmed the "hook" with wire cutters to half as long as "factory" built. Form the big end as you desire, but I find a T handle works for me. If you break one, get a different metal one, as some are more brittle than others. Take the toroid in your left hand (I am right handed, so this is my preference) flat between thumb and forefinger, with the right hand edge of the toroid showing daylight through it. Take the pre-measured length of wire and poke the left end back up through the bottom of the toroid, extending it 1 inch or more beyond the edge of the toroid. Hold that wire there with your left thumb. Then with your right hand, wind the other end of the wire down, away and back up toward you to the top, laying it flat over the top-side of the toroid. With your paper-clip hook, hook up through the bottom of the toroid, hook onto the wire and pull it down, forming a loose loop as you go, and pulling the rest of the wire through. Don't add any friction to the loose end of the wire. Tighten the wire, laying it over the top of the toroid again, hook on and pull down again. Repeat as needed to get the required turns. For practice, I used the core of a scotch-tape roll to perfect my skill, with some scrap wire. It became a natural movement quickly. If these directions are insufficient, please order/get/rent/borrow a copy of the ARRL book _QRP Power!_, and read the sidebar . Sorry I don't have the page number. I will post that tonight. 72/73's De WA7WJA, Bob in Tigard, Oregon (Pronounced "Oh ree gun") ++++++++++++++++ From: "Kempter, Bob" To: "'elecraft at mailman.qth.net'" Date: Mon, 4 Mar 2002 21:17:21 -0800 Subject: [Elecraft] Toroid Winding Reference Hi All: Here is the reference I wanted to post for those interested in looking at the detailed original item: ARRL book _QRP Power_, 1999, p3-10 sidebar titled "Secret Toroid Knowledge Revealed" 72/73 de WA7WJA, Bob in Tigard Oregon ++++++++++++++++ Reply-To: "Don Wilhelm" From: "Don Wilhelm" To: , Subject: Re: [Elecraft] Checking Toroids brfore Soldering Date: Wed, 6 Mar 2002 20:00:46 -0500 Ron and all, I don't know the actual inductance of the toroids - I have not measured mine, but if you are certain you used the correct core and they are wound with the correct number of turns, then they are correct no matter what any inductance meter or other calculation says. Perhaps in the next re-write of the manuals Elecraft will include the 'correct' inductance values for the toroids - particularly the RFCxx toroids. In short - put away your inductance meter and put the perscibed number of turns on the toroids - and be confident that it will work. BTW - always count the turns going through the center of the core and not necessarily the turns around the outside - with toroids, a single wire straight through the core is 1 turn (in this case there would be no turns on the outside - contemplate that to realize the importance of this subtle point). 73, Don Wilhelm - Wake Forest, NC W3FPR home page: http://www.qsl.net/w3fpr/ QRP-L # 485 K2 SN 0020 mailto: w3fpr at arrl.net *** Life is what happens when you're making other plans -- Mike Cross *** ----- Original Message ----- > Has anyone checked their toroid inductors after winding them with a DMM > (inductance) to see if they agree with the values shown in the schematic or > apendix A? I was checking the values to see if I didn"t pick the wrong > toroid out of the little envelope. Well, RFC14 and RFC16 measured value > didn't agree with the K2 Appendix A, they were about three times higher. +++++++++++++++ Date: Wed, 06 Mar 2002 20:22:38 -0500 From: mychael morohovich To: elecraft at mailman.qth.net, RMariutto at aol.com Subject: Re: [Elecraft] Checking Toroids brfore Soldering RMariutto at aol.com wrote: "Has anyone checked their toroid inductors after winding them with a DMM (inductance) to see if they agree with the values shown in the schematic or apendix A?" Ron- Elecraft recommends that builders do NOT try to adjust their coils to the exact values shown in the manual. Rather, wind them according to the supplied instructions and trust that everything will be fine :-) . Keep in mind that some coils may vary by as much as much as +/- 20%, especially given the differences in inductance meters. As for RFC 14 and RFC16, measurements I have performed indicated that the values shown in the schematic are off by the amount you suggested. I tend to believe that to be the result of an error in the documentation. Congratulations on passing the test! Mychael Morohovich / AA3WF K2# 1025 ++++++++++++++++++ From: "Brian Wruble" To: "'Mychael Morohovich AA3WF'" , Subject: RE: [Elecraft] Another K2 Toroid question Date: Sat, 8 Mar 2003 11:54:09 -0500 Thanks! This is quite amazing. I have asked only 2 questions on this reflector. Each time I get several responses even before I see my own posting reflected to me. You guys are great. 73, Brian -----Original Message----- From: Mychael Morohovich AA3WF [mailto:giantbug at earthlink.net] Sent: Saturday, March 08, 2003 11:44 AM To: Brian Wruble; elecraft at mailman.qth.net Subject: Re: [Elecraft] Another K2 Toroid question Brian- What you are describing sounds fine. If the wire was the exact length needed for the finished product, it would be tough getting a handle on it as you approached the last of the turns. I leave the leads close to 1" on the toroids I provide in my prewound sets, but in most cases 3/8" will easily suffice. As with the wire length, a little extra doesn't hurt . Incidentally, Elecraft supplies sufficient enameled wire in their kits, even if you make a few mistakes and have to do some reworking, so don't worry about running out. Mychael AA3WF K2# 1025 ++++++++++++++