Ok I was referring to a design that was using one core to make a 4:1... I think the caveat that was being used was that they felt they could do this and be safe enough with it still being a balun as long as the load was floating (but I'm not 100% sure thats really the case)...
So is a multi aperture core good enough for that or would two toroids be a better idea? ~Brett (N7MG) On Fri, Jul 23, 2010 at 11:00 AM, Tom W8JI <[email protected]> wrote: > << > This sounds really similar to a lot of plans that I've seen... One > other piece that I've noticed on many of these that no one seems to > ever mention is that the two 1:1's are usually wound in opposite > directions on each half of the core... I'm assuming this helps to > reduce the coupling between the two 1:1's? Also I'd be interested to > hear people's thoughts on this "improved balun"... Seems to be an > attractive solution. It only pictures the schematic here and I kinda > picture it as being wound similarly but you wire one of the turns on > one of the feeds from "out" side to "in" side. Essentially the ends > of the wires would fold back over the core to get to its location>> > > If you are talking about two cores in the balun, and each core wound with > half turns and then flipped with a transposed winding, everyone who has > measured the fancy winding concludes it does nothing overall except move > things around. > > If you are talking about winding two 1:1 baluns on a single common core and > using that to make a 4:1 current balun, I can guarantee you that will not be > a balun. It will unbalance any balanced load placed on the balun's balanced > terminals. Each transmission line transformer has to be on its own > independent core. They cannot share a common flux path. > > 73 Tom > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
