Alan G3NYK,

OK on the notch filter design, but for a high impedance load.

I have often wanted to try a notch filter in a low impedance feeder, for
such purposes as reducing a TV line oscillator harmonic or other carrier
type of unwanted signal that is a few kHz from the wanted signal, as the
unwanted carrier can paralyse a noise blanker from working effectively (the
bandwidth of the noise blanker is necessarily relatively wide).

On searching for information on notch filters I found a very good series of
articles in Wireless World.  Part 2 of the series in September 1979 deals
with low impedance notch filters.  The circuit used in "example 4" is a
variant of what you used, with L and C in the leg to ground.

If you can locate old copies of WW you could try modelling a low impedance
notch filter.

73, Bob ZL2CA