> The downside being that ready made cables usually have > molded-on plugs, so you can't fit a keying circuit inside. No, there is no need for a "keying circuit" or level shifter with the K3. It is RS232 levels on both the computer and K3 ends. Furthermore, the CONFIG menu lets you choose which pins (RS232 signals) are used for CW keying and/or PTT. 73, Ed - W0YK