Appreciate the comments Jake! As far as the AM detector goes (D74), I
was able to improve the distortion issues considerably by using a 1 Meg
resistor connected from the -10V rail to the diode's cathode. The AM
clarity was noticeably improved as was the low signal S/N ratio. Terry
Fugate from the Yahoo Kenwood R-2000 group did numerous experiments
with different detector diodes and biasing them in his R-2000 and
achieved some respectable results. It was just pure luck that the R70
had a negative rail for direct biasing with just the addition of a
resistor.