Here’s an article by Nashua Area Radio Society member Mark, KC1IML that explains how to build a PTT switch for remote operation of our station via SmartSDR. Mark and others have been using our station remotely to work DX and operate in the Nashua Area Radio Society’s Student-Teacher Contest Series.
Source: PTT Switch for Remote Operation – Nashua Area Radio Society
And here is a link to a more current USB to serial adapter for use in this application. You can learn more about the Remote Operating Gateway setup at AB1OC-AB1QB here.