[Elecraft] K3 Serial Interface

[Lyle Johnson]

> In order to download and install new firmware do I need only
> pin 2 (RXD), Pin 3 (TXD), and Pin 5 (Common or SER C) connected in my serial interface cable from the computer?

Yes, only these.

> The schematic shows, in addition to the above, some handshake connections:
> Pin 7 (RTS) and Pin 4 (DTR).

These are for KEY and PTT inputs supported by some programs.  They are 
not used in firmware downloading.

73,

Lyle kK7P