Headset Wire Weirdness

[Wage Slave]

Any one else comes across this? Conductors covered in a super thin plastic coating of some kind. Even the shield conductor - every last strand of it. Ditto the signal conductor tucked away in insulation.

Never seen this stuff before and it had me scratching my head for a while. Sandpaper doesn't work and anyway there isn't nearly enough metal to work with. A cigarette lighter will burn it off and expose the conductors but they still hate solder with a passion.

Anyone found a better solution that burning it off? Horrible stuff.

[Joe]

I've come across it frequently and have found that 'scrape and hope' is the only way to proceed.

- Joe

[Wage Slave]

Horrible stuff. There is so little metal to work with that any mechanical method just shredded the wire. As I said burning it off with lighter followed by IPA clean up did work but it still didn't solder at all well.

I was left wondering why I bothered when a new set is so cheap from China but you know what it's like once you get started on a repair and you don't want to let it beat you.

The manufacturer seemed to have got it to solder fairly well so there must be a chemical stripper of something you can use.

Edit to add: It's this stuff and there is a reason for it. There should be an effective way of stripping the damn stuff though.

http://en.wikipedia.org/wiki/Litz_wire

[Tedzed1]

I have often come across this, usually on the cheaper items.
Like Joe, the only way I have found to strip it, is place the wire between Stanley knife blade and thumb
and pull through a few times.

[Yorkie]

Supposedly, the method of cleaning and tinning Litz is (or at least was) to separate the conductors, dip them in meths and set light to it. The meths burns just long enough to clean the wire, but not long enough to burn it. That's the theory, but when Litz was in vogue in the late 50s for home wound coils, I soon discovered that the difference between theory and practice in practice is much greater than the difference between theory and practice in theory. Every time I tried this stunt, the wire incinerated in the routine manner. I quickly abandoned that malarkey and resorted to using 1000 grit wet and dry paper and teased out each separate wire, gently abrading it with the wet & dry paper till each strand was clean enough to tin. I saw an article a while back which gave figures for the extent to which the performance of Litz degrades when some of the conductors didn't conduct. It didn't make a great deal of difference. I always felt that using Litz in tuned circuits was a sales gimmick, with no discernable improvement in performance over a single conductor.

I don't know, but I would have thought that current production Litz wire was self-fluxing and solderable without cleaning, like most enamelled coated wires these days. Might be worth a try. I dare say that on production lines they simply dip the wire in a molten tin bath to tin the ends - done in a jiffy. They're clearly not going to faff around with wet and dry, meths, or any other stunt that takes more than a couple of seconds.

[pwdrive]

Litz wire was used in the old IF transformers giving a much needed higher Q, I wound some homebrew IF transformers once with single wire, the response was a bit flat.
WWV at 60 khz use Litz wire in their transmitter coils, Litz wire reduces skin effect up to certaim frequencies.
It is a sod to tin though, with enameled wireI never bother trying to scrape the ends I just burn it of with a fully loaded soldering iron.

Lawrence.

[Wage Slave]

Well thank you all - I just hope I don't come across it again but at least I know better how to handle it if I do. It wouldn't have been so bad but I thought I could take a section out of the main lead, strip it and get the 7 inches or so of very thin shielded cable I needed to replace the snapped one in the microphone boom. On top of discovering that was not the case at all although it looked like it, I had the fun and games with trying to re-connect the wretched stuff. Not my finest moment or most elegant repair.

When I had repaired the damage I had caused I accepted the inevitable and headed off to the shop to buy a metre of the thinnest and non Litz shielded which thankfully threaded through the mic boom even though it wasn't nearly as stiff as the original wire. Being non Litz made no apparent difference to the sound. Surely Litz costs more than standard wire so I am surprised that it is used on such cheap kit.

Anyway, I start to question my rationality at times. A new headset costs nothing much so why did I spend so long on it and why did I want to try and fix it without having to visit the shop even for a bit of wire?

Keeps me away from strong drink and fast women is, I suppose, the best I can offer.

[Yorkie]

You may know that in the UK we have 'pound shops' such as 'Poundland' and 'Poundworld' - I don't know if you have anything similar in Japan, but I imagine so. ('125 Yen' shops!?). They sell things such as boom mics, headsets, earphones etc. They're surprisingly good, and cheap enough to use as 'donors' for the leads or other items. (Scientific calculators for a pound - how times change!).

Glad you got sorted - elegant or not, the electrons aren't fussy!

As to questioning your rationality in effecting a repair - don't worry, you're among friends - we're all a bit barking mad. I'll spend half a day trying to mend a toaster than I could replace for a tenner. It's not as though I have time on my hands and nothing to do with it! In my case, it's a generational thing - it has nothing to do with rational thought or economics - it's that my brain is hard wired to the 'Make do and Mend' era, having grown up in the 1940s and 50s. Rationing didn't end until I left school in 1954, but it made little difference if you didn't have the money to buy stuff.

I guess that at times, we all spend far more restoring some radios than they're ever worth were we to sell them. Indeed, from a purely financial point of view, it would make more sense to remove the valves, the output transformer, dial and speaker, sell them individually and throw the radio away. But fortunately, that's not how we are 'programmed' or why we are in the hobby. It's not about economics - few hobbes are - it's about the enjoyable relaxing (if often challenging and frustrating!) use of our scace leisure time. At least I think so.

[Wage Slave]

Yes, agree completely with you but I do wonder sometimes .....

We do indeed have something called 100 Yen shops and have had them for a fair bit longer than the pound shops have been in existence. When I first came here, 100 Yen was about 40p so they really did look absurdly cheap. We also have 100 yen a plate sushi restaurants but that is another tale.

I haven't seen mics and headsets here in the 100 Yen shops actually. Perhaps because Skype, along with most internet innovations, isn't as big as it is elsewhere. Plenty of earphones though and as you say I could have probably pinched a lead one from those. In this particular case the thing was a tricky and rather tight fit - perhaps that is what spurred me to go for fixing it.

The good thing about the 100 Yen shops is that there are masses and masses of hand tools which surprisingly are often perfectly acceptable quality for hobby use.

[Skywave]

I'll spend half a day trying to mend a toaster than I could replace for a tenner. It's not as though I have time on my hands and nothing to do with it! In my case, it's a generational thing - it has nothing to do with rational thought or economics - it's that my brain is hard wired to the 'Make do and Mend' era, having grown up in the 1940s and 50s.

Ditto here; it's the challenge, isn't it? Besides whether you succeed or not, you hone your diagnostic and practical skills in the process: always a worthwhile investment.
Sometimes people say to me: "But you make it look so easy!" "Yes" I say, "but you haven't seen the failures!"

Al.