The calculated solution for 650 to 500 is 969 nH and 3 pF.
It seems to me that the only way to actually find the correct solution is to lift the filter out of the circuit.? Terminate it using a 500 ohm resistor, and put a NanoVNA on it to measure the R +/-j.? Even then, the NanoVNA is itself a 50 ohm device so an approximation may be to use a 9:1 transformer on the VNA to filter to at least match it to 450 ohms.? Even better would be to use the 9:1 and a series 50 ohm resistor.??
Y1 is known to be extremely reactive over frequency.? The model of Y1 is a complex collection of L/C/R configuration that is highly reactive.? The 650 to 500 solution is an over-simplified description of the actual problem to be solved, which is to match at 45 MHz.
Ford-N0FP
