Rick and all,
Let me try to simplify this a bit (your statements are correct, but
somewhat complex for a noobie) - it is not 'sematics' for those who do
not understand network theory and impedance networks.
Let's not think in terms of an antenna 'tuner', but in terms of an
impedance matching network.
It simply transforms one impedance to another - that is it!
In normal ham applications, it transforms the 50 ohm output of the
amplifier to whatever is presented at the shack end of the antenna
feedline (if it is in range of the max/min component values) - nothing more.
The efficiency of the antenna and feedline are not changed, but by
allowing the transmitter to work into a 50 ohm/non resistive load, it
will deliver the maximum power to the antenna that is possible.
The max power to the antenna will be determined by the losses in the
feedline and the antenna itself. Often compromises must be made. In
the case of the AX1 antenna, the radiator not only is a short length for
the operating frequency, but also has potential loss in the coils in the
base of the antenna.
73,
Don W3FPR
On 9/30/2024 6:11 PM, Rick nk7i wrote:
Jim,
I stand by what I said (and we don't disagree, it's semantics). For
further (group, noob) understanding; an improved definition...
A 'tuner' is a variable impedance matching network; interfacing the
input impedance to the output impedance to allow the most possible
flow of energy between them. (Too many words for a noob.)
It doesn't need to take into consideration of the impedances along the
feed; it matches what it gets (as best it can).
It does zip for any antenna except (once adjusted correctly) allow the
most energy between input and output of the tuner to be exchanged.
THAT is the main benefit, more throughput while the secondary benefit
is less heat and longer life from an 'irritable' RF power source (i.e.
transistors) from mismatch. [You cannot expect long life of any final
of any kind at high power into a gross mismatch of impedance load.
Some devices allow you to learn instantly😮, that you've made a
mistake; others take time to inform you.]
A tuner does NOT make any antenna more efficient; it makes it louder
because the max energy is exchanged. Antenna efficiency, involves a
few more aspects not covered here.
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