Ok, I have still been working at building stuff. Here is the latest piece of what will become a CW transmitter. These boards are 7th order Chebychev low pass filters.
This is the PCB as laid out in ecad. 4 boards per PCB and you can get 5 PCB from JLCpcb for $2 so that is 20 low pass filter boards. A life times supply.
My current project is a 40m CW transmitter, here is the LPF sitting on top of the TX/RX switch.
Filter response plotted with the NanoVNA.
If you want to have your own LPF boards made, here are the gerber files: LPF_Singles





will you share the files for the TX/RX switch also?
Probably. I will have to go and look and see what I did and if it was any use first.