I'm a newbie who's trying to simulate a Chebyshev filter for which I used the calculator at https://www-users.cs.york.ac.uk/~fisher/lcfilter in LTSpice. The behavior I'm seeing in LTSpice (XVII if that makes a difference) doesn't match what's predicted by the calculator.
Here's what I built in LTSpice – definitely not a 171 MHz highpass filter based on the graph.
What am I doing wrong?
Arsenal pointed out in the comments that my range was obscuring things. I adjusted the range to show more reasonable values:
Best Answer
The are two problems. Firstly the graph you are trying to reproduce is linear, but you are plotting logarithmic amplitude. Secondly you are only computing one point per decade, so the 'curve' is made from just a few straight lines.
Change the sweep to linear with 100 points and left vertical scale to linear, then you should get something like this:-