The SMB-BNC cables I ordered from Amazon arrived and they do fit my DC505, but they are very tight, almost impossible to disconnect using just my fingers. Where/are the outputs on the DC505 infrequently used?
The specific cables that I bought (KNARCO) seem to be out of stock now, but I see another (even less expensive) listing from LIVISN. The odd company names (and the price) make me suspect that these are Chinese sellers, but I have no proof of that. The cables I ordered came somewhat inexplicably triple bagged: first a small bubble wrap bag, enclosed in a sealed anti-static bag, and finally in a blue and white ziplock bag.
-- Jeff Dutky