For moderate length coax runs for a scanner antenna LMR400 is the default based on cost vs performance and the advice above about handing off the a smaller cable at the scanner is very good. Others may recommend 75 ohm RG-6 TV coax to save a few $$, which will work to some extent. I prefer to do things once and do it right, so LMR400 is my best recommendation.
The impedance of the antenna change a lot over its frequency ranges and are up to 2.0 which is either 25 ohm or 100 ohm and the BCD536 also swings between 15 ohm and 110 ohm in UHF and the same in other frequency ranges. I believe that having impedance under control will help a lot. Use a splitter at the scanner that will then isolate the scanners impedance from the coax and use a pre-amplifier at the antenna that will isolate the antenna from the coax and load the antenna with a constant impedance.