coverage and angle antenna

Hi all,
How can i adjust my coverage the best.
i have 2 diy colinear(1 with amplifier) made out 8 pieces 75 ohm wire (figured out that 4 will do the same), but i always seem to only get nort nort-east view.
i think i did pretty well with my coverage(301KM). highest floor of the house.
what antenna's do best for lower altitude ,

I am using modesdeco and modesmixer, i find these better that adsb# or rtl1090