Hello All, So I decided to build a new antenna mast, I'll be around 42' in the air including the antenna which is a SIRIO GPS 1/2, I'D Obviously like to pre tune the SWR while its on the ground to get as close as I can to a 1.1 or 1.5, I'm not to sure about the tuning table instructions though as I've never done this, I want to adjust the L Gap to the 27.185 freq range which reads 660MM, I believe 660MM is around 26 inches? that seems like it will be way to high, had a buddy tell me 9 inches for the L Gap. I'm not sure what to do now. Thx for any help.