Litz is often used in SMPS transformers. High power HF transmitters use copper tubing for coils and transformers. Soldering of litz wire is best done in a solder pot using lots of flux. It does get messy as solder and flux wick up the wire strands.
It seems like it's only viable in very specific applications. I'm going to try to come up with a workable way to solder it for us average folks. That will help make it more usable.
Wow! What a great tutorial and video. Super information, well explained, in a manner that the viewer can comfortably (not intimidated, or lost in technical jargon) understand. I learned a bunch! Idea for stripping Litz, for hobbyists... Create a container, in which you can create a current of solvent... Say a repurposed flat, round, 3"/diameter, plastic, food container, with its lid. DIY a magnetic spinner = A motor base, with a magnet mounted to the shaft. Place the container on the base, drop in a piece of Ferrous metal. As the metal spins, it will create a current in the solvent. This is a laboratory device, but I don't know its name. Cut a small hole in the lid, near the side wall of the container; the current will be greatest, there. Pass the end of the Litz through the hole and into the solvent. Wait awhile, for the insulation to be washed away? Just spit-balling, for fun... What else to do at 2:30am? grin. Cheers.
I don't know enough about crystal radios, but when I was building a TMS (transcranial magnetic stimulation) unit, things definitely would have gone boom without litz wire, hahha.
Excellent tutorial! I wrote for years for the Xtal Set Society "Newsletter" and covered most salient facets of crystal radio construction, etc. One article is about a "Coil loom" for winding "Spiderweb" coils like you showed. While I have had success with Litz wire I agree that it's more trouble than its worth. The law of diminishing returns definitely rears its ugly head. Keep up the good work!
Say you want to build a direct tuned radio in the LW or AM band. By using a tuning coil made with Litz wire instead of one single thread of solid enameled copper (0.3 to 0.5 mm Φ) wire, we achieve a merit factor (Q) which is the double. This improved Q, which in turn improves the selectivity of the radio receiver, is the result of the better distribution of the inter-thread stray capacitances. The improvement require a low load factor from the detector. This require a secondary winding on the tuning coil, experimentally determined (between 5 to 10 turns); or a FET connected as source follower (voltage gain = 1)...
Yes, and the winding pattern matters a lot when you get to a high Q. The spiderweb coil is good. A stack of spiderwebs is better. Also: To get better selectivity, a double tuned radio is better.
I have a video where I made spider coil forms that are the common 8 cm with a 4 cm center. Have not done much with them since. I need to find reliable sources and study up on them.
8:20 would be interesting to see those Atmega based one button part testers testing such a wire before and after you break a strand. I believe they show resistance, inductance and capacitance. So it could be possible to rest it without any expensive equipment.
I think Mr. Carlson's Lab covered soldering Litz wire at some point as well. KainkaLabs is an AMAZING channel for radio hobbyists, though. I've never found better information about ferrite loop antennas than what they have, for example. Definitely check them out!
Newer wire is coated with better (and more difficult to remove) plastics. Some have a polyester or similar jacket. Others are all enameled. Old cables were covered with silk. The internal strands with an easier to remove lacquer and other.
Thank you very much for explaining that and helped me a lot to choose which wire. Funny thing, I'm shooting for the lowest possible frequency so I might just be good with a solid strand magnet wire. Also trying to lower the frequency with a thicker insulation so I'm trying it some DC Bell wire possibly dip it in a resin to increase coating thickness.
Solder pots are not terribly expensive, incidentally. I bought some 660/46 Litz wire a while back to experiment with and ended up getting a solder pot and 1 pound of solder from Amazon. The pot was about $25 and the pound of solder cost about the same! It did work to tin 660/46 as far as I could tell, but I had to hold it in the molten solder much longer than I was led to believe I should. It also tends to wick up the Litz wire a bit when you do that because it acts a bit like desoldering braid. I still haven't actually made a coil with that Litz wire - some day I'll get around to it!
Interesting info, thanks. I think the only way for the average person to test it is to test against a known/working coil. I'm sure factories did/do test against a known reading.
I wish I could say I thought of it, but did not. I saw it in a litz wire brochure showing how to use a solder pot (with regular pot skimming and dipping the wire in an arc-motion). There was another place that mentioned commercial wire stripping chemicals are available. Now I'm trying to figure out a DIY method that us average folks can do/afford!
@@tsbrownie In a book I have called "The Boy Mechanic" they suggested drilling a cavity into a soldering iron which could be filled with solder for dipping wire splices. The book is from the early 1900's and the soldering iron in the photo was the old copper tip on a shaft with a wooden handle. The kind designed to be heated up while resting in the metal loops on the top of a kerosene blow torch. The same book also has plans to build radios in another section. There's 4 different versions of this book with many printings. The book has a little bit of everything and I enjoy thumbing through it at least once a year. The projects are a glimpse into a world long gone.
@tenlittleindians I've used those old soldering coppers that were heated in a cute little gas oven. That would probably work since it could reach the abnormally high temperatures required to remove the insulation throughout the cable bundle. A regular soldering iron won't do it.
Here I am at about 6:00 in the morning still thinking about your wire video and not just for the sake of AM radio. I'm reminded about discovering transformers and how they worked in the early 70's and now a half century later they still baffle me with their black magic. Everybody knows if you take a 100 foot extension cord and short it to ground you get sparks and a blown fuse. Take that same extension cord and wrap it around let's say a section of common rebar and you can now short it to ground without the drama because it acts like a transformer. Even stranger; it also works with just the wire being coiled without the iron but it's not as efficient. Thinking about this transformer "black magic" and your Litz wire video and I'm wondering if they ever made something I will name "linear transformers" by alternating the wires inside Litz wire with a mixture of iron wire and copper wire? Just what effect would that have on current, inductance and frequency? I remember a high school teacher that had a laminated core and a solid core to slip inside his hand wound loops of wire to demonstrate the effects. His laminated core wasn't bolted together tightly and it buzzed loudly during the demonstration which hinted at another phenomena related to frequency. Could this interaction be stretched out with mixed multi strand wire of iron and copper in a Litz wire? How would such a wire behave with frequency, induction and current compared to ordinary wire. What if it were just a group of iron wire towards the center of Litz wire with the copper strands wrapped around this core? Would this react similar to a torrid style transformer? Would length have an effect on such a "linear transformer"? I'm sure this has all probably been tried a hundred years ago but we humans often reinvent the wheel by nature.😊
The temperature needed to remove the insulation is above the temp most soldering irons can do. The outer jacket is plastic (polyester?) and turns nasty when you heat it. You can see that on the litz wire photos.
There are types of Litz that has insulation that goes away at soldering temperatures. I used it in some RF transformers. For some things, simply making a "wire rope" out of three lengths of insulated wire is good enough. You get a big Q improvement on your inductor when you go from one solid wire to 3 strands. When you go 3 to 9 and then 9 to 27, tripling makes less and less improvement. Also: Sometimes it is just find to wind an RF coil with #14 (US house wire) and just live with the fact that the copper in the middle is just along for the ride.
I've read about that. The old stuff used to be coated with silk and would turn to ash at normal soldering iron temperatures. Then there's most of the newer stuff that requires something like 600C to cause it to break down completely. Anything less turns it to brown tar that's a mess to get off and gives one lots of opportunity to break wires.
Hey tsb,...Was that Litz wire intended for the "Tank" tuning Coil (About 240uh) with a 365pf Variable cap ?? Yep, your 28 ga Litz is Way off from Recommended #44 or 46 ga....I see Litz mentioned frequently used in Hi current RF applications where AC resistance causes coil Heating probs ..I Wouldn't think a MW resonate LC radio tuner coil (Running in the u amps) would Benefit much with Litz over reg #32ga magnet wire ? ...I'm planning a 48" x 48" box Loop antenna for MW radio receiver...I have 660/46ga Litz ready to wind (130') for deep Fringe DX tube Regen receiver project....Did you Compete your Crystal radio project ??
I have not built a radio with Litz yet. I'm still trying to come up with a reliable way of soldering it that does not require specialized equipment. I've tried the ways I've seen on the internet, and they either don't work or are very unreliable. I don't know which crystal radio project? I don't have any in process right now. Just some thoughts.
What about dipping the end of the Litz wire to be tinned in lacquer thinner then agitated with an acid brush. This may remove enough of the enamel coating to make for good tinning.
Per our prior discussions of DIYing an AM transmitter... I bumped across a YT video where the author created an AM bench transmitter with an Arduino, a Ferrous Antenna and a three more discrete components... two resistors and a capacitor, IIRC. These were not fake videos. It seemed to me that you could rather easily create multiple channels on a single Arduino, to get the cross-talk function that you need.
@@t1d100 I watched both videos (not sure why the second is not here, but I recovered them from the youtube spam folder, so....) He's only getting a couple meters and I have a transmitter that will produce the same power/distance. It's not enough to power the radio. I've got another thing to try, so I've not given up yet!
Each Separate bundle can be Untwisted (Bout 1") , Silk Removed, Strands fanned out & Lightly 400 grit sandpaper Btushed & Plunged & Held into Solder Pot 'bout 10 secs....The correct Solder Temp should melt & Burn away the Strand Insulation (Without Scraping) or without Burning off or Damaging strands & perfectly Tin all strands...Twist all Tinned Bundles together & Dip twisted assembly into Solder Pot for Hopefully 100% all Strand end to End continuity....
I want to see a video of someone doing that, especially with 46 AWG strands. Even wires much bigger break very easily. I've tried many of the things people suggest, and they don't work. Silk is now nylon, polyester, fluoropolymers, epoxy, etc. And most turn into a sticky burned mess when exposed to a flame, and strands many times bigger melt (part of an upcoming vid). I've also tried the meanest stripper chemicals, and they don't even weaken the coatings. Solder pot will work, but it costs $s and how many times will it get used? I can now do the same with a soldering iron. Video coming.
The Correct ga (44ga or 46ga) Litz wire is Deff worth the effort...An adjustable temp Solder Pot is Best but a 15 watt iron will work...If using Multi--Bundle Litz, Separate the bundles & Dip each bundle Separately into Tinning Pot for 10 secs...Each bundle should have 100% Strand well Soldered....Finally Twist all Bundles together & Dip into Solder Pot for another 10 secs....Inspect & Redo if any strands not Soldered...
I didn't know about the Litz wire "Open continuity Strands" degrading issue....How does one Check each Strand continuity after solder pot dipping ??? ...I have a 660 strand #46 Litz to wind & deff want to QC each Strand continuity...Any ideas ??
Do you really have to buy it tho? You could just get the regular insulated wire and then make the overall strand wire yourself, heck, throw a shielding sleeve on it too as well. Making wire isn't trivial, but it's not rocket science either. Most of the times, for old stuff i restore (as a hobby) whenever i do the wiring, i do it from scratch. There's stuff on the market, there's even high quality stuff that mimics the OG aspect, but ... buying a 10 meter roll (random number) to put 60 of wire overall always rubs me wrong. :)) So i end up making it. For tips, you can look into loom making and rope making vids. Watch three or four from both categories and you're set. Bonus for this affair, you can do it exactly how you want it, with the exact number of strands you want, the exact "weave" you want etc. The world is your oyster type thing.
Soldering Litz Wire Easily--No Special Equipment/Chemicals ruclips.net/video/NQHSkUHI4iU/видео.html
Litz is often used in SMPS transformers. High power HF transmitters use copper tubing for coils and transformers. Soldering of litz wire is best done in a solder pot using lots of flux. It does get messy as solder and flux wick up the wire strands.
You have confirmed what I have always suspected; Litz wire is more trouble than it's worth!
It seems like it's only viable in very specific applications. I'm going to try to come up with a workable way to solder it for us average folks. That will help make it more usable.
Wow! What a great tutorial and video. Super information, well explained, in a manner that the viewer can comfortably (not intimidated, or lost in technical jargon) understand. I learned a bunch! Idea for stripping Litz, for hobbyists... Create a container, in which you can create a current of solvent... Say a repurposed flat, round, 3"/diameter, plastic, food container, with its lid. DIY a magnetic spinner = A motor base, with a magnet mounted to the shaft. Place the container on the base, drop in a piece of Ferrous metal. As the metal spins, it will create a current in the solvent. This is a laboratory device, but I don't know its name. Cut a small hole in the lid, near the side wall of the container; the current will be greatest, there. Pass the end of the Litz through the hole and into the solvent. Wait awhile, for the insulation to be washed away? Just spit-balling, for fun... What else to do at 2:30am? grin. Cheers.
Thanks. I think I will try chemical stripping because heat and flame did not do well.
I don't know enough about crystal radios, but when I was building a TMS (transcranial magnetic stimulation) unit, things definitely would have gone boom without litz wire, hahha.
I love the smell of flesh in the morning! So any tips to share?
Excellent tutorial! I wrote for years for the Xtal Set Society "Newsletter" and covered most salient facets of crystal radio construction, etc. One article is about a "Coil loom" for winding "Spiderweb" coils like you showed. While I have had success with Litz wire I agree that it's more trouble than its worth. The law of diminishing returns definitely rears its ugly head. Keep up the good work!
Thank you.
Say you want to build a direct tuned radio in the LW or AM band.
By using a tuning coil made with Litz wire instead of one single thread of solid enameled copper (0.3 to 0.5 mm Φ) wire, we achieve a merit factor (Q) which is the double.
This improved Q, which in turn improves the selectivity of the radio receiver, is the result of the better distribution of the inter-thread stray capacitances.
The improvement require a low load factor from the detector. This require a secondary winding on the tuning coil, experimentally determined (between 5 to 10 turns); or a FET connected as source follower (voltage gain = 1)...
Yes, and the winding pattern matters a lot when you get to a high Q. The spiderweb coil is good. A stack of spiderwebs is better.
Also: To get better selectivity, a double tuned radio is better.
I have a video where I made spider coil forms that are the common 8 cm with a 4 cm center. Have not done much with them since. I need to find reliable sources and study up on them.
@@tsbrownie There is little about them to find because it is hard for a machine to make them.
8:20 would be interesting to see those Atmega based one button part testers testing such a wire before and after you break a strand.
I believe they show resistance, inductance and capacitance. So it could be possible to rest it without any expensive equipment.
A NanoVNA should show two different plots. I don't really consider a NanoVNA "expensive" test equipment 😉
Thank you for your efforts and in -depth investigation.
The youtube channel Kinka Labs video 'How to tin Litz-Wire' is pretty good on this subject. Special trick to tin Litz wire.
I'll check it out. Thanks.
There is also special Litz that is made to be easy to solder. The insulation basically works like flux.
I think Mr. Carlson's Lab covered soldering Litz wire at some point as well. KainkaLabs is an AMAZING channel for radio hobbyists, though. I've never found better information about ferrite loop antennas than what they have, for example. Definitely check them out!
@@flapjack9495 I like Mr. Carlson's Lab channel and he's a trustworthy source . I looked for a litz video on his channel and did not find one.
Litz wire are used in switching power supply where efficiency is important.
Yes, it is.
That was very useful. Is there a time where the isolation is all enemeled wire?
Newer wire is coated with better (and more difficult to remove) plastics. Some have a polyester or similar jacket. Others are all enameled. Old cables were covered with silk. The internal strands with an easier to remove lacquer and other.
Thank you very much for explaining that and helped me a lot to choose which wire. Funny thing, I'm shooting for the lowest possible frequency so I might just be good with a solid strand magnet wire. Also trying to lower the frequency with a thicker insulation so I'm trying it some DC Bell wire possibly dip it in a resin to increase coating thickness.
If you want thick insulation, there is everything from wire wrap wire to small gauge plastic coated circuit board wire.
I purchased 60ft of 180/46 from mikes electronics parts. For $15 plus shipping $5. Thanks for the video. I now know im in for challenge.
It's pretty easy to work with. I found a way to solder both types that does not require any special hardware. ruclips.net/video/NQHSkUHI4iU/видео.html
Solder pots are not terribly expensive, incidentally. I bought some 660/46 Litz wire a while back to experiment with and ended up getting a solder pot and 1 pound of solder from Amazon. The pot was about $25 and the pound of solder cost about the same! It did work to tin 660/46 as far as I could tell, but I had to hold it in the molten solder much longer than I was led to believe I should. It also tends to wick up the Litz wire a bit when you do that because it acts a bit like desoldering braid. I still haven't actually made a coil with that Litz wire - some day I'll get around to it!
Interesting info, thanks. I think the only way for the average person to test it is to test against a known/working coil. I'm sure factories did/do test against a known reading.
The only thing I can come up with is using a solder pot to solder litz wire. But, I am sure you have either thought of that or have tried it already.
I wish I could say I thought of it, but did not. I saw it in a litz wire brochure showing how to use a solder pot (with regular pot skimming and dipping the wire in an arc-motion). There was another place that mentioned commercial wire stripping chemicals are available. Now I'm trying to figure out a DIY method that us average folks can do/afford!
@@tsbrownie In a book I have called "The Boy Mechanic" they suggested drilling a cavity into a soldering iron which could be filled with solder for dipping wire splices.
The book is from the early 1900's and the soldering iron in the photo was the old copper tip on a shaft with a wooden handle. The kind designed to be heated up while resting in the metal loops on the top of a kerosene blow torch.
The same book also has plans to build radios in another section.
There's 4 different versions of this book with many printings. The book has a little bit of everything and I enjoy thumbing through it at least once a year. The projects are a glimpse into a world long gone.
@tenlittleindians I've used those old soldering coppers that were heated in a cute little gas oven. That would probably work since it could reach the abnormally high temperatures required to remove the insulation throughout the cable bundle. A regular soldering iron won't do it.
Here I am at about 6:00 in the morning still thinking about your wire video and not just for the sake of AM radio.
I'm reminded about discovering transformers and how they worked in the early 70's and now a half century later they still baffle me with their black magic.
Everybody knows if you take a 100 foot extension cord and short it to ground you get sparks and a blown fuse.
Take that same extension cord and wrap it around let's say a section of common rebar and you can now short it to ground without the drama because it acts like a transformer. Even stranger; it also works with just the wire being coiled without the iron but it's not as efficient.
Thinking about this transformer "black magic" and your Litz wire video and I'm wondering if they ever made something I will name "linear transformers" by alternating the wires inside Litz wire with a mixture of iron wire and copper wire?
Just what effect would that have on current, inductance and frequency?
I remember a high school teacher that had a laminated core and a solid core to slip inside his hand wound loops of wire to demonstrate the effects. His laminated core wasn't bolted together tightly and it buzzed loudly during the demonstration which hinted at another phenomena related to frequency.
Could this interaction be stretched out with mixed multi strand wire of iron and copper in a Litz wire? How would such a wire behave with frequency, induction and current compared to ordinary wire.
What if it were just a group of iron wire towards the center of Litz wire with the copper strands wrapped around this core? Would this react similar to a torrid style transformer? Would length have an effect on such a "linear transformer"?
I'm sure this has all probably been tried a hundred years ago but we humans often reinvent the wheel by nature.😊
7:20 I am wondering, would hot air work to strip the wire? Does the isolation pull back when you heat it?
The temperature needed to remove the insulation is above the temp most soldering irons can do. The outer jacket is plastic (polyester?) and turns nasty when you heat it. You can see that on the litz wire photos.
There are types of Litz that has insulation that goes away at soldering temperatures. I used it in some RF transformers.
For some things, simply making a "wire rope" out of three lengths of insulated wire is good enough. You get a big Q improvement on your inductor when you go from one solid wire to 3 strands. When you go 3 to 9 and then 9 to 27, tripling makes less and less improvement.
Also: Sometimes it is just find to wind an RF coil with #14 (US house wire) and just live with the fact that the copper in the middle is just along for the ride.
I've read about that. The old stuff used to be coated with silk and would turn to ash at normal soldering iron temperatures. Then there's most of the newer stuff that requires something like 600C to cause it to break down completely. Anything less turns it to brown tar that's a mess to get off and gives one lots of opportunity to break wires.
Are some of them not solvent-based?
@@TimLF I'm going to give that a try next.
@@TimLFSome can be stripped with solvents. This is not all that common and it is not an easy procedure. You have to wash it all away.
Hey tsb,...Was that Litz wire intended for the "Tank" tuning Coil (About 240uh) with a 365pf Variable cap ?? Yep, your 28 ga Litz is Way off from Recommended #44 or 46 ga....I see Litz mentioned frequently used in Hi current RF applications where AC resistance causes coil Heating probs ..I Wouldn't think a MW resonate LC radio tuner coil (Running in the u amps) would Benefit much with Litz over reg #32ga magnet wire ? ...I'm planning a 48" x 48" box Loop antenna for MW radio receiver...I have 660/46ga Litz ready to wind (130') for deep Fringe DX tube Regen receiver project....Did you Compete your Crystal radio project ??
I have not built a radio with Litz yet. I'm still trying to come up with a reliable way of soldering it that does not require specialized equipment. I've tried the ways I've seen on the internet, and they either don't work or are very unreliable. I don't know which crystal radio project? I don't have any in process right now. Just some thoughts.
What about dipping the end of the Litz wire to be tinned in lacquer thinner then agitated with an acid brush. This may remove enough of the enamel coating to make for good tinning.
Good idea. I read manufacturers use chemical strippers. I was thinking acetone, I know I have thinner so that is a good option. What is an acid brush?
@@tsbrownie The acid brush can remove remaining insulation material, which has become goo and still stuck to the conductors.
Per our prior discussions of DIYing an AM transmitter... I bumped across a YT video where the author created an AM bench transmitter with an Arduino, a Ferrous Antenna and a three more discrete components... two resistors and a capacitor, IIRC. These were not fake videos. It seemed to me that you could rather easily create multiple channels on a single Arduino, to get the cross-talk function that you need.
ruclips.net/video/Xy7DiPVi18Y/видео.html
ruclips.net/video/m-EJ7NYxggc/видео.html
Thank you. I will have to search on that.
@@t1d100 I watched both videos (not sure why the second is not here, but I recovered them from the youtube spam folder, so....) He's only getting a couple meters and I have a transmitter that will produce the same power/distance. It's not enough to power the radio. I've got another thing to try, so I've not given up yet!
Each Separate bundle can be Untwisted (Bout 1") , Silk Removed, Strands fanned out & Lightly 400 grit sandpaper Btushed & Plunged & Held into Solder Pot 'bout 10 secs....The correct Solder Temp should melt & Burn away the Strand Insulation (Without Scraping) or without Burning off or Damaging strands & perfectly Tin all strands...Twist all Tinned Bundles together & Dip twisted assembly into Solder Pot for Hopefully 100% all Strand end to End continuity....
I want to see a video of someone doing that, especially with 46 AWG strands. Even wires much bigger break very easily. I've tried many of the things people suggest, and they don't work.
Silk is now nylon, polyester, fluoropolymers, epoxy, etc. And most turn into a sticky burned mess when exposed to a flame, and strands many times bigger melt (part of an upcoming vid). I've also tried the meanest stripper chemicals, and they don't even weaken the coatings.
Solder pot will work, but it costs $s and how many times will it get used? I can now do the same with a soldering iron. Video coming.
The Correct ga (44ga or 46ga) Litz wire is Deff worth the effort...An adjustable temp Solder Pot is Best but a 15 watt iron will work...If using Multi--Bundle Litz, Separate the bundles & Dip each bundle Separately into Tinning Pot for 10 secs...Each bundle should have 100% Strand well Soldered....Finally Twist all Bundles together & Dip into Solder Pot for another 10 secs....Inspect & Redo if any strands not Soldered...
I've cracked the code on soldering Litz. Got to put together a video. But I've found ways that anyone can do. Stay tuned.
I didn't know about the Litz wire "Open continuity Strands" degrading issue....How does one Check each Strand continuity after solder pot dipping ??? ...I have a 660 strand #46 Litz to wind & deff want to QC each Strand continuity...Any ideas ??
My thought is to test against a known good coil. Sounds easy but ....
Thanks 👍
Thank you.
What is .4mm. solid wire? #26?
Correct.
Do you really have to buy it tho? You could just get the regular insulated wire and then make the overall strand wire yourself, heck, throw a shielding sleeve on it too as well. Making wire isn't trivial, but it's not rocket science either. Most of the times, for old stuff i restore (as a hobby) whenever i do the wiring, i do it from scratch. There's stuff on the market, there's even high quality stuff that mimics the OG aspect, but ... buying a 10 meter roll (random number) to put 60 of wire overall always rubs me wrong. :)) So i end up making it. For tips, you can look into loom making and rope making vids. Watch three or four from both categories and you're set. Bonus for this affair, you can do it exactly how you want it, with the exact number of strands you want, the exact "weave" you want etc. The world is your oyster type thing.
Yes, you could make your own. The wire gauge for AM radio is 46, or about 0.0405mm. Most of my radio coils need about 30 meters.