Paul Christensen wrote:
> > This is the point that I have been trying to get across. A bird meter acts
> > as a directional coupler with isolation between forward and reflected only
> > when the load is a pure 50 ohm resistance.
>
> I don't think this point needs repeating. There has never been an argument
> here. See my conclusions from the four-step test I
> conducted. I would still like to know:
>
> 1) Where power is being dissipated when a fully charged automobile battery is
> zero-resistance shorted across it's terminals?
>
> 2) Where 20-amps at 13.8 VDC of transceiver power is being dissipated in the
> absence of a transmission line or load?
>
> -Paul, W9AC
Paul,
You are looking at your bird meter with no termination on it and it is telling
you that there is 100 watts of power going out and
100 watts of power going back to the radio. What we are trying to tell you is
that the meter is lying to you. There is no 100 watts
of power coming out of the radio. The meter in this mode is not functioning as
a watt meter. There is no current flowing in the
line as there is no termination. No current no power. If there is no power
going out there is no power to be reflected back to the
transmitter. You are only seeing voltage that the watt meter is telling you
there is power. It is not telling you correctly.
Yes your final may be drawing current from the power supply when you turn up
the drive. Yes the final is dissipating power. Is it
dc power or rf power. Probably some of both as you will have some circulating
currents in the tank circuit due to the mismatch and
the efficiency will probably be way down. It is all happening internally.
73
Gary K4FMX
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