http://www.nature.com/nphoton/journal/v7/n4/full/nphoton.2013.45.html http://www.nature.com/nphoton/journal/v7/n4/full/nphoton.201... Here's a definitive src on

http://www.nature.com/nphoton/journal/v7/n4/full/nphoton.2013.45.html http://www.nature.com/nphoton/journal/v7/n4/full/nphoton.201... Here's a definitive src on .69c for an 'ideal' fibre velocity factor. Here are two sources, both of which have prop. velocities @ around .6c depending on the dialectric. Again ideal. I haven't architected any long-run infrastructure, but 1/3rd sounds pretty right to me. https://cdn.shopify.com/s/files/1/0986/4308/files/Cable-Delay-FAQ.pdf https://cdn.shopify.com/s/files/1/0986/4308/files/Cable-Dela... http://www.faculty.ece.vt.edu/swe/lwa/memo/lwa0136.pdf http://www.faculty.ece.vt.edu/swe/lwa/memo/lwa0136.pdf RG58 is your traditional coax copper you'd run with copper and SMA connectors on an above-average scope.