[TowerTalk] How to mix concrete in the mixer

[VeeAthreePL]

I am just about (this coming weekend) pour my concrete base for TX455 
tower. Foundation for it is going to be 4 X 4 X 6 deep.
I'll be using a mixer to make the concrete (cement).
Can anybody tell me a proper ratio of Portland Cement to gravel.
How many pounds of portland I need?
I heard that I should use 1 to 3 ratio but I also hear that 1 to 10 is 
good enough.
Which one is correct?
What is the proper mix to get 3000psi concrete, then?
I think I ask too much!!!

73 to all Andy - VA3PL