[time-nuts] Re: Rooftop GNSS antenna mounting recommendations

[Matt Huszagh]

Bob Camp via time-nuts <time-nuts at lists.febo.com> writes:

> The survey poles are a bit smaller in diameter than the typical patio umbrella. Some amount of
> shimming may be needed to clamp them into the stand.

Can you elaborate a bit on this point? The linked survey pole is 1in
diameter and the second stand supports 1.5-1.9in. Do you do something to
increase the diameter of the pole, or maybe replace the screw clamp with
another, longer screw. Or, place something else in there alongside the
pole?

> With asphalt shingles some sort of rubber mat is a good idea. The shingles do a lot better with
> some sort of spacer between them and a weight.

Good to know, I'll do that.

> A simple test once you get it up there: give it a bit of a shove. If it moves more than you think it
> should, go find some sand bags and put them on the stand. I’ve never had one go wandering
> when used as an antenna mount (and never needed additional weight).
>
> If you can rope it off to something structural, there’s no downside to that. In the event of an
> issue it likely would help.
>
> Keep in mind, this is all assuming the roof is dead flat / horizontal.

I haven't actually been up there yet, but from my deck it looks like
it's just a bit off horizontal. If it's not perfectly flat, the pitch is
very small though. Is that likely to be a problem? When I go up there
for the first time I can measure the actual pitch.

Thanks for all these recommendations Bob - this is very helpful!

Matt