I've also heard that the native impedance a twisted pair of WD1A/TT is about 150ohms. In my application, I use two parallel lengths of WD1A/TT, spaced about 4.5inches. Each twisted pair acts like a single conductor, and the Z of the two parallel lengths is about 450 ohms. I didn't know the variants of WD1a used different conductors. My earlier comments refer to the twisted pair variant, with each conductor comprised of a mix of fine steel and copper strands. 73, Jim w8zr
Sent from my iPhone > On May 9, 2020, at 6:16 PM, Mike Waters <[email protected]> wrote: > > Exactly, Dave! It's right in my Beverage antenna page ("145 ohms"), along > with several different calculators. :-) > > And all WD-1* wire is *not* the same. Back when I used to sell Beverage > transformers, people would send me short samples to measure before I wound > them. You have to accurately measure the spacing and wire diameters to > determine that, unless you have a long enough piece of it to use an antenna > analyzer (preferred). > > The 6.25:1 is okay for the feed end, but NOT the reflection transformer. I > corrected that on the former w0btu.com, but the archived page implies > otherwise. > > 73, Mike > W0BTU > >> On Sat, May 9, 2020, 6:52 PM Artek Manuals <[email protected]> wrote: >> >> More like 150 ohms as I recall >> >> Dave >> NR1DX >> >>> On 5/9/2020 7:34 PM, Mike Waters wrote: >>> Fred, those transformers are the wrong impedance ratio for WD1! They are >>> for 420-450 ohm wire. WD-1 has a much lower impedance. >>> >> >> > _________________ > Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
