I remember wbw a 100 foot piece of -48V 500 MCM being modeled as R+jinductance and C to trough. We were wondering what impulse it would take to raise -48V to 0. Turned out a disgruntled employee was pulling the fuse. KISS
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On Wednesday, July 7, 2021, 12:56:52 PM EDT, David Eckhardt <davearea51a@...> wrote:
A DC source has no complex portion and is not characterized by impedance,
only the real term in the R ¡À jX.? Further, if no current is drawn from the
source, the presence of the R term isn''t there.? The ¡À jX term requires AC
and is absent for DC.? However, once you draw a varying current from that
DC source as in SSB or keyed RF (CW), then the complex portion appears.
Example:? Take AWG #000 (or whatever) large solid copper conductor.? At DC,
the cross sectional current density is homogenous.? However, even at 60 Hz,
skin effect due to resistance and inductance (+ jX) is evident and
measurable.? The cross sectional current density is no longer homogenous
even at 60 Hz.
Dave - W?LEV
On Tue, Jul 6, 2021 at 9:53 PM Jim Lux <jim@...> wrote:
On 7/6/21 8:46 PM, Anne Ranch wrote:
My favorite question , not directly related to nanoVNA
Why is having minimal SWR important ?
Optional answer:
SWR is an indicator of IMPEDANCE match between x and y devices -
directly related to "power transfer" between. source - TX - and load -
antenna.
Demonstrate by applying Ohm's law.
Which breaks horribly if your source has very high or very low impedance
- Consider a DC power supply.
--
*Dave - W?LEV*
*Just Let Darwin Work*
