I have had soil transmitters for years. What I did was sink a pipe near where I wanted to plant 4 sensors. Fastened the transmitter to that and it worked for me . I am sending you a picture I did a while back . You can see the transmitter on the pipe, I also had a second transmitter. Each of the pvc pipes has a pair, one sensor and one temperature probe at 4,12,24,36 in. I think this would work better than slanting the transmitter and you will be glad you asked.