Evan,
I installed the filter originally after the AGC. I found I had strange distortions on the bands that I could not explain since the BCB filter I installed looked good on a sweep and had an attenuation >80db with one of the notches tuned to the frequency of the local transmitter(WHAM). I proceeded to probe the line with my spectrum analyzer and discovered that those products were caused in the AGC when my AGC pot (4.7Mohm) that I installed in the off position was in a certain range.I installed it to make the AGC adjustable something that i.m.o. really helps the receive . I think that the distortions are produced in one of the FETs and stem from the very strong signal of WHAM radio. Installing the filter before the AGC solved the problem. It was easy to do using very thin coaxial cable. The problem may or may not show up with the fixed step AGC or with a lower AM station input level.
John
Btw, the Station is so strong here we could hear it in our land line telephone? before we got rid of it and went to cell phone and it is audible in the background of most commercial audio amplifiers.I god rid of my audio system that used cables to the speakers and installed a blue tooth audio system. That solved that problem.
