I was instructed by nvidia support to post this question here for possible help. Perhaps someone might point to a possible problem.
There are few of us who have problems with connecting HackRF to K1 and trying to use RF Analyzer from Play Store.
Talking to original developer and looking at my logcat I was told that the K1 errors on this line. Source is on GitHub and Toast prints failed message. https://github.com/demantz/hackrf_android/blob/master/src/com/mantz_it/hackrf_android/Hackrf.java#L281
There is also interesting talk about this at https://github.com/demantz/hackrf_android/issues/2
I myself did try several different cables and Y-splitters and all fail at the same line.
What is the maximum Amp draw at 5V from K1 OTG?