Looking at some ready made N scale catenary that is European I found quite a bit in different lengths ranging from 80 mm to over 200 mm. I dug out my double track masts and placed them at about 130 mm on the tracks. 100_0357-2 by John Moore posted Jul 24, 2020 at 12:45 PM 100_0358-3 by John Moore posted Jul 24, 2020 at 12:45 PM To my eye that appears to close and I am thinking about placing them at 230-240 mm or about 9 inches apart. Maybe further if I can find the ready made wire in those lengths. Doing more research I found that 300 mm would be right for US straight ways and that works out to near 13 inches. Here I have set the masts to about 13 inches and I like it better 100_0359-5 by John Moore posted Jul 24, 2020 at 1:20 PM Of course the mast would be closer together on curves.