Anybody know a cause for ERR PTT on KX3 powerup?

The Digirig has been working well for over a month. I have one of those $60 laptops from Microcenter (runs on 12V!) and have been running FT8 using a KX3 quite successfully since I got it.

ETA: I’ve been using WSJT-X and FLRig for FT8, using CAT for PTT

Now I appear to have screwed things up, and I can’t remember how I managed, though I might have plugged an unpowered DR into a powered KX3. I content that this shouldn’t have killed anything, but I’m a software engineer, so I kind of know better (or should…)

The problem I experience is an ERR PTT message on powering up the KX3 if the red mic plug is inserted. The KX3 just kind of locks up then. Some test scenarios:

  1. if the red mic plug is inserted, ERR PTT displays
  2. if the red mic plug is not inserted, normal KX3 startup
  3. after normal startup, inserting the red plug keys the transmitter.
  4. SSB operation is normal, using a home-build footswitch/mic/PTT box

After 35 years doing embedded software for all manner of stuff, this sounds an awful lot like a hardware failure on the DR, perhaps a blown port - a cable failure matching this description is hard to imagine.

Right now I’m in the “I killed it, but whatever I did shouldn’t have killed it” camp. I’m wondering whether you’ve heard of any issues like this. I already reset the KX3 to defaults, but this is something else.

Is there a diagnostic utility that I can run to check? Can I flash a new image without buying a new emulator?

In the interim, I’m just going to buy another. It’ll be handy in other circumstances.


Well, once again, stupidity prevails. The audio plug had pulled out just a smidge (that < -0.5mm in EU terms), but it was enough to make wrong contacts. I still ordered the other unit, though, configured for a different radio.