[TowerTalk] Re. Impact of Reflected Power

[DavidC]

What about the timing issue some have explained at HF -- the signal is
moving so fast that it obliterates the impact of phase concerns -- at least
for the sort of narrow bandwidth signals we Hams use?

I agree that it all sounds ugly, having our signal rattling up and down the
feedline, but I guess it happens so fast that it is almost as though it
hasn't happened at all.

73, DavidC  AA1FA

> Naaaahhh, cant be.  If initial sig hits antenna, and part of energy is
> reflected back to amp, then all of that is reflected back to ant, then we
are
> already getting these two sigs out of phase.  then if part of that is
reflected
> back to amp, then reflected back, we are even more out of phase. 
Depending on
> the transmission line length and its velocity coefficient, pwr nulling by
> phaseout would seemingly take place.  Even if this is wrong, I just dont
like
> it, i tell ya!
>     Peace, Doug - Nx4d
> >
> > So, are we agreeing to conclude that reflected power that is resolved
by
> > the final tuned circuit of an amp, rig, or antenna tuner is meaningless
and
> > to be ignored as irrelevant at HF frequencies?
> >
> > I am using "resolved" to mean that the amp or rig is protected from
> > troublesome voltage, current and/or impedance's.  I am also using it to
> > mean that essentially all reflected is re-reflected back to the antenna
and
> > directed to its intended destination.
> >
> > One question:  If one adds a group of toroid beads to the coax
immediately
> > exiting the amp or rig (some say this helps with impedance stability
and
> > eliminating rf in the shack), what is the actual result?  Is any
> > significant loss injected into the system design?
> >
> > Thanks & 73, DavidC  AA1FA
> >
> > > Reflected POWER has little to do with anything except as it affects
> > > voltages, currents, and impedances by presenting a different
impedance to
> > > the PA.  73 Tom


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