OK, there is one thing, I want to wa
rn you about this Johnson's angle meter:
I
t MAY BE OFF.
Probably, it's odd, but mine was. I did installation in April, when my black shingle roof was hot...
I could not get my mast plumb from all the sides.
And, as for newbie, it took me an hour to figure out(and to scorch), the angle metter is off by 2 degrees: so when it's perfect vertically aligned , it shows 2º.
Maybe I will post a picture later, but still, before using, test it with a regular bubble level. If you know the error is 2º, you still can use this tool successfully