The Initial Step Size of Quarter Scans is 20, but surely the Initial Step Size should change for each Quarter Scan? So the 4th Quarter starts at 133,000 Hz. According to my calculation, the Initial Step Size should be approx 33.

You could modify the other scans to use a larger step size is you wish, as the starting frequency is larger.

However, I think you missed the original intent of the quarter scans. The intent is to scan the same frequencies as the All Full System Scan. The process was cut into quarters only to allow those who can not complete a full scan in one sitting to get something back. Using the quarter scans as it is comes at a cost -- you are not getting your top 20 hits, but rather the top 5/10 from each quarter section of a full octal range. There is a difference.

If you modify the step size, you modify the frequencies scanned, and they no longer match. You are no longer scanning the same 3800 frequencies once you put all of the 4 scans together.

If one later decides they can sit a bit longer and use say the half scans, or even the full scan, and later wanted to compare hits across scans, the data collected would not be usable if the frequency maps did not match.

The choice is yours to modify if you wish. However, from the big picture point of view, we won't be modifying the templates in the system.

One other point if you go to modify the step size.

Ensure that the frequencies to be scanned are evenly divided by the step size, while maintaining frequency overlap.

133,000 - 152,000 = 19,000 Hz to scan. The MOR overlap for 133,000 = 33.25 Hz

19,000 / 33 Hz = 575.757575 Frequencies to be scanned.

For more details, please check the link:
https://www.spooky2.com/forums/viewtopic.php?f=79&t=8787