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Old June 9th 10, 01:33 AM posted to rec.radio.amateur.antenna
Keith Dysart[_2_] Keith Dysart[_2_] is offline
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First recorded activity by RadioBanter: May 2007
Posts: 492
Default Question about "Another look at reflections" article.

On Jun 8, 6:30*am, joe wrote:
Keith Dysart wrote:
These simple thought experiments definitely helped my understanding.
Some of the assertions that have been made can be shown to be false
when tested with these waveforms and analysis.


...Keith


Here is a thought experiment for you.

* * * * * * * * * *A * * * * *C * * * * *E
* * * *+----\/\/\--+--/\/\/\--+--/\/\/\--+--/\/\/\--+
* * * *| * * * * * * * * * * * * * * * * * * * * * *|
* * * --- * * * * * * * * * * * * * * * * * * * * * -
* * * *- * * * * * * * * * * * * * * * * * * * * * ---
* * * *| * * * * * B * * | * *D * | * * *F * * * * *|
* * * *+-----------+-----||---+---||-----+----------+
* * * * * * * * * * * * *| * * * *|

Four resistors, equal value.
Four DC sources, equal value.
Voltage A-B = 0, no power past here.
Voltage C-D = 0, no power past here.
Voltage E-F = 0, no power past here.

No power crossing the boundaries on either side of the resistor between
A and C. The resistor is not directly connected to a supply, how is it
dissipating power, if any?

(Yes, I do know the answer.)


Very nice. How about:
A C E
+------+--/\/\/\--+--/\/\/\--+----+
| |
| |
| |
| B | D | F |
+------+-----||---+---||-----+----+
| |
In any case, ABCD do not form a network, being, in fact, two
disjoint networks. All bets are off.

Consider:

+------+--/\/\/\--+--/\/\/\--+----+
| |
| |
| |
| B | D | F |
+------+-----||---+---||-----+----+
| | |
-----
---
|
| A C E
+------+--/\/\/\--+--/\/\/\--+----+
| |
| |
| |
| | | |
+------+-----||---+---||-----+----+
| |
There can be current flowing at C and at D, as well as a large
voltage difference between C and D, but these have nothing to
do with each other and are not an indication of energy flow.

For Cecil, using Google Groups, look for 'Options' and select
'Fixed Font'.

....Keith