I have a ten foot dish I dug a hole 5ft deep and welded cross supports to the pipe below ground level for added support,they don"t have to be pretty you will never see them once you pour concrete.Don"t just drop the pipe in the ground and pour concrete.I then strapped a one inch electrical condit to the mast and stubbed it out of the hole,after you pour the concrete and set the post and dig your trench for your coax,you than have a "tunnel for your coax" that looks nice.I don't know how to post the picture from my "smart" phone to show you.Take pride in your installation,post a picture when your through.Good luck ps I used an 8ft digging bar and a digging set for digging telephone poles by hand to dig the 5ft deep hole,as you are aware once you get down about 30 inches it becomes very hard to get the dirt out of the hole.