Michael Shaffer wrote:

I'm putting up a satellite dish and I need a 12' 3.5" OD pole, would
Home Depot sell this? I don't want to go to a plumbing store, $$$.

Plumbing supply houses are the ones that sell iron pipe in 20' lengths,
which sounds like what you need, a 20' piece of 3 or 4" iron pipe.
You'll probably want galvanized, or face a lifetime of rust.