Isn't this getting to be more like Litz wire?
Mel, K6KBE
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On Sunday, January 31, 2021, 07:01:29 AM PST, Manfred Mornhinweg <manfred@...> wrote:
Dave,
True, but then I don't get enough turns on the toroids for 160-meters.
That's when you try to use the same thick wire.
You can make a pretty good 50? balanced line by twisting together 4 relatively thin wires with teflon insulation, and interconnecting the diagonally opposed wires at the ends. You can try different wires to get the impedance close enough, by making short lines (1 meter) and using the NanoVNA to measure their impedance on VHF, with the Smith chart function.
Such a twisted 4 conductor wire could end up with a better ratio between width and power handling than a simple parallel line.
But then, of course, making 50? line is rather pointless when you will use the CMC in a random impedance system. I just wanted to point out that it is possible to make a balanced 50? line that has reasonable size and power handling. And such a line might be useful in 50? systems, because it is easier to wind than coax cable of the same size. Specially when made from stranded wire.
I think it would be worthwhile to test the RF qualities of the ultraflexible silicone-insulated wire offered in many sizes by Chinese sellers. I bought a few rolls of it to use as hookup wire. The strands are 0.08mm thick, and the heavier wires are made from hundreds or thousands of these strands. Together with the silicone insulation, the wire is extremely flexible and would be easy to wind even in very tight places. Also the insulation is quite thick, which is good to avoid corona-related breakdown. And silicone resists high temperature and high voltage. I just don't know how good or bad it is in terms of RF dielectric losses. Maybe I should make such a line, measure the losses and report back...
That wire is available in several colors, which is useful to visually identify the ends in a 4-wire line.
