Magura

it's easy when you are winding them on lathe (or milling gadget) , not sissy winding machine

Difference mainly being, that a lathe does not hit the max weight limit Magura

I would rather unload the truck of bricks than wind a 90 mH air core coil - don't know why but I'm really reluctant when it comes to coils (maybe because I worked many years with short-wave transmitters) and that makes your work even more impressive in my eyes. Your fancy coils I won't even comment

If I had the choice, I'd too take unloading a truck, rather than winding those coils, any day Nasty type of work if you ask me.Then you should also know how nice coils are (once made that is), I for one have had some very nice experiences with inductors, and as the copper price has gone down a bit, they're not even all that expensive anymore.As Zen Mod says, I used a lathe for winding them, but to tell you the truth, it didn't make much of a difference to how sore you get -And no, we don't have that much equal rights here, that I get inductors served for a hug and a kiss Magura

Here you can see one of the more fancy solutions. A shielded inductor, for the CLC filter.To make a shielded air-core inductor is not as simple as it may seem. It requires a balance of ferro-magnetic and non magnetic shielding material, to leave the inductance unchanged, and not get in trouble with saturation. This I got around, by making a "cup" of ferritic stainless steel, and a base that doubles as a heat-sink, of copper.To get the heat transfered to the copper base, I have potted the whole thing.Magura

WOW ! You must have inherited a copper mine!Really impressive!I thought you'll use some toroid transformer's center taped secondary - this way, with air core inductor, it will hardly find a way to average DIYer's heart Nevertheless, keep up the good work and please keep us informed on progress!

If only I had inherited a copper mine That would have made this a little less daunting to the bank account Actually, I am just an average DIY'er, but have spent a little more time than most are willing to. This construction is really not that much more expensive, than what you frequently see people build. I just have put the money where I thought it is important, and haven't spent them on silver capacitors and fancy wire.Magura

what's the "BIG DONUT" choke ?

The "big donut" is a 2 x 90mH air core choke. The "big" part of "big donut" , refers to its physical size. Approximately 350mm diameter, and 120mm tall. Some 20kg of copper Magura

Which has been populated by now.Some of the components will look familiar to the members from behind the ex-iron curtain.Magura

One of the latest steps: A machined PCB. Initial layout by Spavleski, trimmed to snuff by yours truly.Magura

So, here is a little something.This project has been ongoing for 8 years by now, and for some strange reason it's about to come to an end.The electronic part is the result of a collaboration between Zen Mod and yours truly.The box is the result of my need to escape the reality from time to time First a schematic:Magura

So, a little something to start up this forumMagura