Download the app called network cell info, go to Map tab and locate the base station around your house. The GPS location is usually off by a bit, if you have time to drive around and find out the physical location, it will help with your aim. Try to locate base stations within 2km radius of your house. If it is near lesser populated area it will be less congested. If you have a rooted phone, download Network Signal Guru when you are nearby the base station, helps to tell you what Cell ID is the base station. Each base station has their unique Cell ID. Some base station Cell ID support multiple bands, some base stations only have 1 band.
I found that placing antenna with windows closed can help to filter out the noise outside. If I place the antenna at the balcony, I get connected to shitty base stations. With Yagi antenna attached, the signal is so noisy that I cannot get a lock. If I place it inside,with windows closed but antenna correctly aimed, I get connected to my preferred base station. My antenna is now beside the sofa aimed to the base station in my living room. Luckily for my case, I live high enough that the physical base station is visible from my balcony near a lesser populated area. Does not make for a tidy environment, but I don't get many visitors.
The difference is between connecting to a 1-2 bar , and 4 bar base station.
If you try all this and you still cannot get a good base station, there is another trick. Go inside your house and aim it to the other side. i.e. opposite of your balcony, maybe in the room or your kitchen or wherever. It does not need to be near a window. Because there are so many walls in between you and the Base station, B3 would be a better choice, but no harm checking out B7 as well. Room corners serve as a natural antenna and can help to reflect the signal to your CPE but YMMV. Once you found the sweet spot, place it around your room for optimum signal strength. From what I tried, if my antenna was placed in the room corner near at the room closest to the Apartment entrance, I got 3 bar with 10Mbps ish on B3. The base station was a good 2km away!
Adjusting the antenna placement with the Huawei Toolbox only helps with your antenna orientation by noting the SINR and RSRQ numbers. Usually it does not jump to another base station until you restart the modem.
All my experiments are attempted on the E5786 with the MIMO antenna.
Thanks for that extensive write up. Much appreciated.
Regarding that close-window-to-reduce-signal-noise trick, I found that I get 1 bar extra on the B310 once I close the window on which my antenna is hung close to. As of 6 PM today I managed to get 3 bars for LTE on B8 (900 MHz). It started with a download speed of 10 Mbps tested on fast.com then, but slowed down to 2 Mbps as of now - congestion perhaps ? Dunno really ... but the B310 still shows 3 bars.