Hi Rich, here we go with the fly excrement in the pepper again!
.The discussion was about in circuit adjusting a network with an rf
analyzer/bridge. No mention of L networks, etc. When you connect a resistive
load of
the correct value to the input and an rf analyzer to the output of an L
network or Pi network , you can adjust for 50 +j0 at the analyzer. As you
know,
j0 means no series (or parallel for that matter) reactance is present. Also as
you now, that is what we commonly consider "resonant".
Your point about the L and Pi networks not being resonant is mute. We are
trying to confirm that the network will transform the equivalent plate load
impedance to the desired output load impedance, 50 ohms in this case. since
there is more than one solution to doing this and there are obscure
contributors
to the network values, there is a risk of screwing up. Hence the need to
confirm that the impedance transforming network is working as expected or at
least
close to expected. By observing the values of C1 and C2 we can also
determine if the network operating Q is at or near the expected value.
Can one expect to set a network in this manner and never touch it again?
Maybe if the Q was <1 but in the case under discussion, not likely. I would
wager you a case of your favorite suds though that the PA would fire up making
more than 50% of expected power.
Resonant or not, I know of no safer, easier or more accurate way to cold
test an output network. Do you?
My Sincere Regards,
Gerald/K5GW
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