This is my line of sight to the west. My balcony is above the rooftops at the end of the street. Intertwined in the balcony was terrible. 4' above the roof big difference. To the east... forget about it though.
With antennas, height is just about everything. Getting it up above the surrounding structure can make a huge difference, as you experienced.
If it's working well, then changing out the coax will not likely make a big difference. In other words, if you can hear it now, changing the coax will not likely make a noticeable difference, unless you have something that's right on the edge of being useable.
Likely, changing out the scanner to a newer one will improve things more noticeably.
Feels kind of good to do it yourself, doesn't it?