To drastically increase the Q and thus the notch depending on whether the circuit is in series or in parallel one can lower or increase the impedance of the filters with impedance transformers at the input and the output of the filter. It would add complexity and likely lower the TX output.
Il 10/nov/2018 07:20, "iz oos" <
and2oosiz2@...> ha scritto:
Right Brian, I don't really understand that as well. Maybe it might make sense but I should see how the schematics would be. The 91mhz might make sense to notch out the harmonics of 45mhz if this is the cause of the spur. Apart from the resonances I would look at the Q factor as well.
