Homer, I figured out what was wrong with my overlay pattern noted above. I used the wrong trace for the overlay.
Here is the correct trace over the regular I-10K model and this agrees with the details above which now shows the 1.08 dbi difference in the gain between regular radials and shortened radials.
View attachment I-10K with short radials overlay over stock.pdf
Here is the correct trace over the regular I-10K model and this agrees with the details above which now shows the 1.08 dbi difference in the gain between regular radials and shortened radials.
View attachment I-10K with short radials overlay over stock.pdf