Ok, so I've been working on getting simple first-order passive filters working in a simple circuit. Say you have something like this:
**broken link removed**
I have a 555 circuit in astable mode with a pot to control the frequency as the input into the filter circuit. I'm then measuring the output voltage of the filter circuit. When I change the frequency of the 555 circuit, the filter output hardly changes at all. I know that this first order circuit doesn't have a very steep transfer function so the change will not be very quick, but you would think that as you approach the extremes, the voltage would drop a good amount but it doesn't. Any suggestions?