The receiver is definitely worth recapping at some point.
Moving back to my original question that started this thread...
If I was going to build one of these in-line filters there are certain input values I need to calculate the specs of the filter. What exactly are those specs and are they listed in the below information?
Tuning range: FM, MW
Power output: 75 watts per channel into 8Ω (stereo)
Frequency response: 5Hz to 75kHz
Total harmonic distortion: 0.03%
Damping factor: 50
Input sensitivity: 6mV (mic), 2.5mV (MM), 150mV (line)
Signal to noise ratio: 78dB (MM), 95dB (line)
Channel separation: 55dB (MM), 65dB (line)
Output: 150mV (line)
Speaker load impedance: 8Ω (minimum)