For the last 1.5 hour polarization dropped from -43% to -32.9%
Scanned microwave frequency in the range from 70.355GHz to 70.430GHz.
Found two spots (70.370GHz and 70.386GHz) for which polarization drop is minimal.
Kept running at 70.370GHz
Previous TO's frequency records before anneal was 70.40GHz