[Elecraft] serial cable connected to the K2 by accident

[David Woolley]

g4ilo at qsl.net wrote:
> What normally happens is that you blow the auxbus, and end up with a dead 
> radio. Since yours still works, you probably got away with it. Perhaps 
> there was nothing connected to that pin on your cable.

That sounds like an accident waiting to happen!

Ideally Elecraft wouldn't have used a 9 pin D connector, but, as they
have, I think I may isolate that pin initially, maybe by not installing L1.

Some other thoughts were:

- connectorising the signal on the jumper cable;
- connectorising L1;
- inserting a back to back plug and socket into the D connector
   to isolate the non-standards lines.

It sounds like the other risky signal is the 12V one, but I think the
worst that happens is that the filter choke acts as a fuse.  It also
isn't at risk with normal RS232C signals, only with the ground
connection.  Is it worth trying to add a PCB mounting fuse?  Would the
voltage drop be too large?