| Simple FTDI PTT & CW Keying Interface - VK4GHZ |
| Simple FTDI PTT & CW Keying Interface - VK4GHZ This interface uses the RTS and DTR signal lines from a cheap FTDI USB Serial Adapter, and provides isolated keying for both PTT and a CW key. https://vk4ghz.com/simple-ftdi-ptt-cw-keying-interface/ |