For some reason, up until very recently, I've found it incredibly difficult to actually find any 4G cell phones on band 20 of the RF microwave spectrum. It's always been easy to see the base station transmitter signals but looking at the area in the spectrum where phones are supposed to be just came back completely and utterly blank! To say this was confusing is a massive understatement, but inspired by having the project get into the quarter finals of HAD 2017, I called upon the assistance of some neighbours to give me some technical advice and practical assistance.

Lured by the smell of coffee infused with chocolate mint, my actual next door neighbour came over and very generously wandered around the garden watching videos on YouTube via 4G until I was able to get a fix on her phone signal using the LimeSDR and GQRX software to work as a spectrum analyser:

Why has it taken me so long to get this result? It must be something to do with the relative positions of the transmitting phone and the receiving antenna connected to the Lime? If the two are very close together does the receiver get overpowered by the very strong phone signal?