I would really avoid RTV. That stuff has some caustic chemicals that could potentially damage electronics. I forget what's in it.
They make some tar like sticky stuff that you can wrap around coax connections to waterproof them. I used to use the stuff, but I found that it was almost impossible to get off in the winter, so I've stopped using it. I'm probably eventually going to get water in my lnbs and switches, but I hate that tar stuff.
On my big dish, I finally made a little junction box, a weather protected plastic box, where I have barrel connection unions so I can access the coaxes and connect a meter, etc, without taking the coax off the lnbs. But with my little dishes, I just put the lnbs and switches in plastic bags. However the bags degraded, ripped, and are no longer protecting anything, so I'm probably going to have problems eventually. I also haven't used the terminators that Rainman referred to. I know I should, but I didn't. So far I'm lucky I guess. Also, I don't really try to seal the plastic bags, I just keep the open side down. I once did this and sealed up the end with duct tape, however this tended to trap moisture inside the bag, which would condense after a warm/humid to cool cycle, and this was worse than being out in the rain. I just let the bags breath.
Those switches though are really leaky. Someone here posted about them not being waterproof a while back, and I didn't beleive it, because I didn't see any reason that they *couldn't* be waterproof, so I took an old bad one apart, and sure enough, they are not sealed through the coax connector, you can slip a wire through the coax connector, and it goes clear through into the internal electronics spaces. That wasn't necessary. They easily could have used connectors that were waterproof, or could have encased the whole circuit board in plastic, but I guess that would have been more expensive.
I don't know if the
QPH-031 uses waterproof connections or not. I'm hoping that it does, since I'm not terminated, and I'm not using waterproof connections on my coaxes, but I'll probably find out sooner or later. So far, I've been lucky.
But if you don't intend to take the coaxes off in cold weather, then you might look for some of that tar like coax seal material. It is supposed to be safer for electronics than RTV, and if it's not too cold, you can peal it off then re-use it. It works well, but it's not good when it gets cold.