Getting up higher in the city definitely got my device to reach more nodes. Here is an article from the Meshtastic site on increasing the range which discusses line of sight & how elevation is important to increase the range https://meshabout.com/increase-meshtastic-node-range-maximum-distance/
Good to know when setting up nodes. Put em high. Also makes them harder to mess with.
I also bought a replacement antenna for my Heltec to help reach nodes better than the stock antenna. Can't remember the cost but somewhere between $10-$20 on Digikey. Apparently antennas on Amazon or Aliexpress are not always what they claim to be so best to purchase from a reputable outlet specializing in electronics etc