I needed a low pass filter for 432MHz and as usual Ali Express has a solution not to expensive. These were 400-470 MHz low pass filters. Mine started at 385 MHz going down.
I decided to try and retune them by pulling the small inductors apart. This result in the following plot:
The loss for each filter was about 2.5 – 3 dB
The soldering of the inductors was poor, on one filter I had to resolder the inductors. Sorry for the bad photo!
