CW RX Update: Band Pass Filter

So i rewound the inductors, after lots of stuffing about I got them ball park.


Ran the filter up in the bode analyzer and well the filter part looks close enough, but it still needs more inductance, maybe another 2 turns per toriod to get the center frequency up to where I want it. Now, that second hump in the plot at 21mhz, I got no idea why that is there, when you look at the next plot where i inject 20mhz into the filter and look at the output on the scope, you will see it does not exist in reality, but shows in the bode analyzer.

Filter output at design frequency.

Frequency output where that hump is on the bode plot. Its obviously an aberration in the analyzer and for now I am not sure why its there.


Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.