Hi Andy,
I have been reading over the page you linked to and it was a very interesting read. I tried using the method detailed in my first post and I did seem to get a resistance around what was predicted - it was a little tricky to get a spot on reading as the output of my filter was a little wobbly at the top no matter what I did so I had to pick a reasonable place to take my measurements.
During my information searching process some videos appeared on Youtube by Larry Benko (W0QE):
His videos explain the workings of a piece of software called SimSmith:
This software allows you to do real time plotting of Smith charts and SWR plots and is really excellent. I have been watching Larry's videos for the last few days and have have been modelling my filter using the methods shown in his videos. Once modelled you can create a matching network and adjust it in real time and watch how well it works on the SWR plot.
Using this software makes it really easy to see how well your theoretically calculated values work so you have a really good place to start when get the soldering iron out.
Starting with the values from SimSmith I fiddled about a bit with my matching network and now have a reasonably good looking filter response, it is 2KHz wide so should be good for SSB which is my main objective.
Thanks again for the suggested page,
Kerr
