[Elecraft] K3 unexpected TX after iMic + CocoaModem

[Don Wilhelm]

Tighe,

Check your menu CONFIG: PTT-KEY entry.  Set it to OFF-OFF and see if the 
problem stops.
Something in your computer setup is probably activating either RTS or 
DTR or both.

73,
Don W3FPR

On 2/16/2014 8:01 AM, Tighe Kuykendall wrote:
> Strange issue and haven't found much by searching.
>
> I use a MacBook Pro with my K3 and KX3.  It had worked fine for rig 
> control and with the K3/P3/KPA utilities.  I added an iMic audio 
> interface (bought it for the iPad and was experimenting) and setup 
> CocoaModem for use with the KX3 to do digital modes.  When I connected 
> the MBP back to the K3, any type of USB activity for rig control or 
> the K3/P3/KPA utilities causes the K3 to go into TX which can't be 
> stopped except by unplugging the USB from the MBP. If there's no USB 
> control activity with an app, the K3 works normally.
>
> I simplified the radio down to just the K3 with no other accessories 
> and it still happens.  KPA utility works as expected with the KPA, 
> even with the K3 powered ok and it going into TX.  I checked for 
> grounding issues and reseated all of the serial cables.  The USB ports 
> work normally for everything except interfacing to the K3.  I tried a 
> different MacBook with the K3 and it works fine, so it's something 
> with the MBP side of the USB connection on my shack laptop.
>