Thanks to Owner-Manuals.com! This manual was exactly what I needed. As Amana was purchased by Maytag and later by Whirlpool, there was no way to receive it from their websites. I was lucky to find this resource.
Great to be able to set channels again, on an old but stoll fine working TV
Text excerpt from page 20 (click to view)
3-12.
Model 10811A/B Find the line on Table 3-1 corresponding to the oscillator's aging rate. Then find the maximum allowable error (accuracy) on the horizontal axis. Follow the maximum allowable error vertically until it crosses the oscillator's known aging rate. Move horizontally to the left and read the minimum calibration interval in days. maximum allowable error known aging rate (per day) = calibration interval in days
Example: 5 x 10-9 (maximum allowable error) 3 x 10-10/day (known aging rate) 3-13. 3-14. = 16.67 days (~17 days) 3 X 10-10/day (known aging rate)
From Table 3-1, the oscillator should be adjusted approximately every 17 days. The minimum calibration interval may also be determined from the following formula: