Hi there… We purchased a few of the DMK USB FOBs awhile back after homebrewing a few. When I was down in Virginia at company HQ last month, I spent a few nights trying to make this work to no avail. We have an old IFR service monitor which I was using to generate tones and such. We’re using an Icom commercial repeater IC-FR3000/4000. The Icom has no internal controls for rx or txaudio that I can find (documentation is very slim). Basically, rxtune doesn't want to work with the audio coming off the Icom repeater discriminator. I did not try deemphasized audio as I want to keep everything flat. In looking through some of the old posts we are seeing similar results whereby rxtune doesn’t see anything. But oddly enough, if I used the HT to generate DTMF tones, the * box would detect them. The transmitted audio I could not get more than 2 or 2.5 kHz deviation with the audio coming out of the * box. As a side note, when we were using the homebrew USB FOBs we had louder digitally generated audio (didn’t have the service monitor then) than repeated audio. Got any ideas to try? Thanks leon wa4zlw