VSWR doesn't matter?
On Mar 12, 11:53 pm, Roy Lewallen wrote:
Yes! All that matters to the transmitter is the impedance it sees. It
doesn't know or care that you've mathematically separated the delivered
power into "forward" and "reverse" components. It doesn't know or care
what the SWR is on the transmission line connected to it, or even if a
transmission line is connected at all.
Think about this - if the transmission line is exactly one-wavelength
long
and lossless, the transmitter sees exactly the same impedance as the
load. At the load, we know reflections occur, but they are same-cycle
reflections so during steady-state with no modulation, exactly the
same
conditions exist at the transmitter as exist at the load if the
transmitter
has the same impedance as the transmission line. So even if we
cannot measure the reflections back into the transmitter, they are
no doubt, there - that is, unless one denies the existence of
reflections
in which case, one needs to explain how standing waves are possible
without reflections in a single-source system.
--
73, Cecil, w5dxp.com
|