I just recently scored a working Modulation Sciences FM ModMinder. It's been a while since I used one, but plugging this one, I was immediately reminded of how sensitive they are to RF levels. It's got to be just right with this thing. My old Belars, and my Inovonics 531, are all happy with the RF level of the sample ports, but not the ModMinder. It's sensing a low RF level. I tried adjusting the small nylon screw on the Harris sample port (turning it in, and then out), to try and get more RF signal, but it seemed to make no difference on the signal level of the Inovonics 531. Any suggestions?