5G signal doesn't penetrate buildings/walls/solid objects very well, so yeah you really need to know where your mast is, and the router needs to be on the correct side of the house, with as little solid objects between it and the mast. So, a single wall, or a window - no obstruction is obviously best but the more direct line of sight you have, the better.Thanks - I had assumed outside would be better but I'll try again inside.
There's only one mast pointed our way according to cellmapper which makes things easier. I've tried a few spots inside but couldn't find a good spot. What's the relevance of knowing where the mast is - should I be trying that side of the house, near (but not in) those windows? I also found lining the router up so the longest side faces the mast provides a better signal.
I think I'll try putting the sim inside a phone to make it easier to move around.
In the window is fine, but on a window sill right next to the frame you might have issues, I found lifting it up 12 inches so it's away from the frame was fine.
Plus, height is generally a good thing.
I'd stick with using the router, the 5G antennas in it will be much bigger than your phone antenna.
In simple terms, once you know which direction your mast is, put the router in the room facing that way to start, and then plug it into an extension reel and start putting it in various places in that room.