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Old August 30th 03, 01:41 PM
Tarmo Tammaru
 
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"W5DXP" wrote in message
...
Tarmo Tammaru wrote:
...and all reflected power was re reflected.


Since the re-reflected waves are coherent with the source waves,
how do you know that? Would the amplitude of ghosting in a TV signal
support that assertion?
--
73, Cecil http://www.qsl.net/w5dxp


There was no actual power generated by the source. Some people seem to think
that *power* dissipated by the resistor due to current flowing in one
direction and *power* caused by current in the other direction cancel. Of
course, the experiment was moot, or 1/4 wave stubs wouldn't work. Ghosts
live in the realm of pulses, where things always work unambiguously. In
logic design, you often terminate the source, so there is only one
reflection. You can't series terminate the load, because the input impedance
is several K; you can't shunt terminate the load because the source can't
deliver enough current, although I have done things like shunt terminating
the load with a Zo resistor in series with 10PF or so.

Tam/WB2TT