Yes, I biffed it yesterday in initially quoting ¦År. I entered the
published velocity factor of 0.91 instead. My error. However, the
effective ¦År can be derived from Vp as: ¦År = [1/ SQRT(Vp)]. So, given my
measured Vp of 0.87, ¦År = 1.07.
When I measured the center-to-center spacing of the conductors, I was quite
surprised. I have always assumed the standard window line consisted of
1.0" spacing. Mine is definitely 0.85" spacing. Surprise to me.
Dave - W?LEV
On Fri, Feb 26, 2021 at 1:09 AM Roger Need via groups.io <sailtamarack=
[email protected]> wrote:
On Thu, Feb 25, 2021 at 02:59 PM, David Eckhardt wrote:
Measured wire center-to-center spacing is 0.85-inches
Wire is stranded AWG #16 stranded copper weld
Using an ¦År of 0.91, the physical parameters indicate Zc more like 430 to
440 ohms
using the calculator at:
Why an ¦År of 0.91 ?? Air is 1.00054. When I put your wire spacing
(21.6mm) and conductor diameter 1.29 mm) in I get the following for air 420
ohms. What is the ¦År of windowed ladderline that is often made of
polyethlene? Impedance will go down as ¦År goes up....
Roger
--
*Dave - W?LEV*
*Just Let Darwin Work*
