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Old July 28th 06, 07:39 AM posted to rec.radio.amateur.antenna
Richard Clark Richard Clark is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 2,951
Default Reflection on Resistive loads

On 27 Jul 2006 20:30:57 -0700, "palaniappan chellappan"
wrote:


I am trying to understand forward and reflection power
throught practical circuits , instead of going through books.


Hi Palani,

The remainder of your post suggests you should go through the books.

I found forward/reverse power meters measure reverse
power by measuring the phase difference between current
and voltage at load terminals.


WRONG. However, what you say is right by parts. They measure
voltage, they measure current, and they measure differences, but not
in the simple manner you describe. The sum of the parts does not
equal the total of the statement.

If current and voltage
are in phase, there is no reflection . am i correct ?


WRONG. See following:

if it is correct ,
if transmitter has 50+j0 ohm output impedance , and if i connect
antenna tuned to 100+j0 ohm. (assume no long cable is used ,
directly connected ) , reverse power is zero ?


12% of the power is reflected with a 2:1 (100:50) mismatch, not zero.
Current and voltage are in phase (resistive load by your definition of
100+j0 ohm).

73's
Richard Clark, KB7QHC