On 02/10/2014 08:34 PM, Doug Crompton wrote:
Another thing to consider on the DMK is RFI. They are very susceptible to it especially higher power HF but be aware that any RF could cause problems. I have had this happen at two different locations. The fix was ferrites on the leads in and out. One on each lead worked for me but more may be necessary depending on the severity. You can also wrap multiple turns through a single ferrite if they fit.
This shows up a a locked interface and usb error messages that in my case specifically said EMI? It might not always catch that it is an EMI problem though so other errors might indicate the same thing.
Since the DMK is nothing more than a fancy USB sound FOB I suspect any FOB might have this problem. Lead length both audio and USB would also be a factor.
Agreed. I am curious, though, what voltage is sent back to the USB buss from the device. My reasoning is, that in -my- case, when this happened, I noticed that if I pulled the USB cord, let it set for 15 or 20 seconds, then plugged it back in, the green light lit up, and as soon as it Transmitted, that URI died, again. Shutting down the machine, to the point of letting the caps discharge, etc, then bringing everything back up, plugged in, all worked flawlessly... until, at least, I RF'ed the system again with HF signals from 75 and/or 40m.... ~sigh~ 73 = Best Regards, -Geoff/W5OMR