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On 25 Oct, 09:38, Cecil Moore wrote:
art wrote: At first I was considering the actual wire length in the braiding b ut that influence became little compared to the current pertabutations. Sounds like you are working on a self-resonant coil and need to know the length of time for the current to flow from end to end. Both sides of the argument are wrong on that one. The current does not jump from one end of a coil to the other in a very small number of nanoseconds as one "expert" has asserted which implies a VF close to 1.0. Neither does the current follow the wires directly round and round the coil as asserted by the other side which would imply a VF around 0.01. The actual measurable VF of a coil seems to be just about double the round-and-round argument side as there is indeed some coupling between adjacent coils. A typical 75m Texas Bugcatcher 6" dia, 6.5" long, 4 tpi coil has a VF of around 0.02 making it about 40 degrees long at 3.8 MHz. -- 73, Cecil http://www.w5dxp.com No Cecil you are following a fatal aproach by using lumped loaded circuitry which is a no no when measuring current speed. Especially when you are following a path of zero standing waves. To obtain a voltage doubling you can only solve by using distributed loading aproach where a single wire has approx length when measured close to the ground short of two wavelengths . Unfortunately by using braid to get extra current perbutatation the length extends quite a bit longer even tho braiding electrical length is longer that the physical measurement. Ofcourse the introduction of a flyback transformer would be exciting but we must not run before we walk Regards Art |
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