Not sure whether I am being sensible in chiming in on
this one ...
Most of what most have posted is correct. Seems to me
that some people think that lots of Watts go hurtling
down the line, are reflected by a mismatched load, and
are then dissipated in the PA. However, a standing
wave is just that and has the effect of changing the
impedance seen by the PA. Any peculiar effects in the
PA are due to it seeing a peculiar impedance. (Well,
perhaps not quite ANY!) When a wattmeter reads more or
less power than is actually being transfered it is
because of the relative phases of voltage and current
at any given point in the line. The meter is reading
Volt-Amperes NOT Watts unless the line is properly
terminated.
73 Roger
VE3ZI
__________________________________________________
Do You Yahoo!?
Everything you'll ever need on one web page
from News and Sport to Email and Music Charts
http://uk.my.yahoo.com
|