Question on winding aircore inductor by hand

[yukyukyuki]

I want to hand make a 0.22mh coil. I use Shavano"s reference, 60 turns (39 ft.) of 14 AWG wire on a 1.34 inch bobbin. I shall borrow someone's reactance meter to get the desired MH. The question is:
I cannot make parallel layers as some turns are overlapping each other randomly. Does that matter ?Or are there any simple methods to wind the core?

[Jonathan Bright]

hi yukyukyuki, Neville Thiele (of Thiele-Small fame) wrote an article for "The Journal Of the Audio Engineering Society" on aircored inductors some years ago and I recall he made the point that radom winding of the wire seemed to be quite stisfactory. If he found it okay then I suspect the rest of us can. By the way if you are winding many aircored coils you might try tracking this article down as it was very practical and revolved around a novel way of looking at the problem. If I find my copy I'll post the reference.

[gfinlayson]

I've wound quite a few of my own coils. I used a short section of 22mm copper tube, with two rings of MDF squeezed onto it the right distance apart. The rings keep things tight and allow perfectly parallel layering. It probably doesn't make them perform any better, but it makes the coils look much neater:





Here's another very useful coil designer. You can change all of the dimensions of the coil to suit. It also tells you the weight and length of wire required and works in AWG, SWG or metric.

[jackinnj]

Inexpensive, acurate, sound-card impedance meter:
The sound card impedance tester is here

[waltona]

Slightly OT but I notice that Gfinlayson is in the uk.

Where do you get your enammelled wire from? Having looked at Maplin and RS prices I decided that it was probably as cheap to buy readymade inductors.

Cheers

Al

[Ron E]

Originally posted by Jonathan Bright
hi yukyukyuki, Neville Thiele (of Thiele-Small fame) wrote an article ...

The Thiele method is what is in the Loudspeaker Design cookbook and also what the Shavano calculator uses. It is also the logic behind the graphs in the Weems books. FWIW, Weems said that scramble wound coils work OK as long as the windings are not too messy.

I think that winding coils is not worth the effort, it might have been a few years ago when large gauge coils were hard to find, but they are easy to find and not much more expensive than the copper nowadays....

[Cal Weldon]

Back in the days when a 5mH coil cost 5 bucks, I decided I was going to wind my own and save some money. As it turns out it cost me 6 bucks of magnet wire and about a half hour to wind the same coil. And mine never did look that purdy.

I have not compared prices recently. Actually, not in the last thirty years. I just buy them.

[Puggie]

There is a real lack of decent inductor supplies in the UK. A friend of mine got some 16 Gauge stuff for winding some inductors and I have some 12Gauge. I'll try ang get some details but its still not cheap, £10 per kilo with 10kg min order rings a bell, + Vat + P&P of course.

Do you know anyone with a small lathe, that speeds things up a lot!

[KCC]

the thing about self winding coil is such that you can wind to whatever the value you desired,which often is not available in the market.

[Cal Weldon]

If that's the case, don't you buy an oversized and unwind it?