-----Original Message-----
The ubiquitous t-network tuner with series capacitors and a shunt inductor
(like the MFJs) is a high-pass filter, so it won't help a bit.
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Not quite right. As a counter example, think of a pi network. It should be a
low pass filter, right? But is not. If you tune a PI network to a frequency
higher than the signal frequency you get practically no output. Same is true
with a T network. If it is tuned to a frequency lower than the signal's the
output drops. This is because the chosen component values are for impedance
matching rather than simply a low pass or high pass filter. You have over
looked resonance. Yes, in the T more harmonic power will pass than in the Pi.
But, not as much as you may imagine. Particularly when you are matching very
different impedances.
Try it. Tune your amplifier to 30 meters into a dummy load and then switch
your driver to 40 meters. This test is only valid if you have a untuned input
circuit. Do you get an output? It should be a low pass filter and 40 meters is
a lower frequency than 30 meters. Same is true with the T matching network.
73
Bill wa4lav
ot quite right. As a counter example, think of a pi network. It should be a low
pass filter, right? But is not. If you tune a PI network to a frequency higher
than the signal frequency you get practically no output. Same is true with a T
network. If it is tuned to a frequency lower than the signal's the output
drops. This is because the chosen component values are for impedance matching
rather than simply a low pass or high pass filter. You have over looked
resonance. Yes, in the T more harmonic power will pass than in the Pi. But, not
as much as you may imagine. Particularly when you are matching very different
impedances.
Try it. Tune your amplifier to 30 meters into a dummy load and then switch
your driver t
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