[Elecraft] K3S PTT using DTR/DTS issue

[Lyle Johnson]

Hello Jerry!

I am not sure what you mean by "I'm already using the USB for control so 
will just use it for PTT. "

You can certainly use USB for audio and RS232 for serial control. If you 
use RS232 for serial control, you need to set up the menu for the data 
rate.  You must also use RS232 for RTS and DTR in that case.

If you set up for USB for serial control,then you must use RTS and DTR 
over USB as well.

I have plugged in USB<->RS232 cables between my computer and the KIO3B 
using the supplied RJ-45 <-> DE-9 cable and it worked fine.  I have also 
done this using USB for audio.

No smoke ever escaped during all of this testing and use.

I cannot diagnose what may have failed or why, but it sounds like the 
computer system may have a different power ground return than the radio 
system and there may have been current flowing though the RS232/USB 
connection as a result.

Hooking a serial port to the supplied serial port cable with the menu 
selecting RS232 should cause no problems, and using USB with the menu 
selecting USB should cause no problems.

I have had things hooked up and had the menu in the incorrect selection 
(RS232 but only USB physically connected, or USB with only RS232 
physically connected) with no physical damage, though of course the rig 
did not communicate with the application under those circumstances.

73,

Lyle KK7P


> So my new K3S is running well and I'm setting up my software and see that it
> can do digital modes and control PTT using a comm port. I open my owners
> manual, page 20, which says I can use that connection for control and PTT.
> I'm already using the USB for control so will just use it for PTT. I have a
> USB to serial adapter so I install it, plug in the RJ47 connector to the
> rig, mate the DB 9 connectors and immediately smell burning components,
> Quickly disconnect the DB9.