AUTOMATIC DIGITAL INTERFACE KEYING WITH TIMING FOR PULSED DIGITAL MODES

摘要

The April 2005 issue of QST containing Larry Coyle's article, "An Improved Digital Communication Interface," arrived at just the right time. I was preparing to improve my own interface, which did not have isolation or automatic keying. It had worked well until I replaced my ICOM IC-735 with a Kenwood TS-940. My system now exhibited a hum problem. I temporarily retired from digital modes to avoid polluting the airwaves. Building a new interface moved onto my long projects-to-do list. The urge to operate using Hellschreiber mode pushed this project to the top of the list.