I just got my QCX-20 assembled and i'm having an issue I haven't seen talked about (though I could just be blind) - without plugging in headphones, I started trying to align the BPF, and couldn't get a peak (it always stayed around 4-5).? ?I looked over all the parts and solder joints and such and everything looks good.? So, I plugged in headphones to hear this loud tone when aligning - but I actually get a loud clicking as soon as the unit is powered on, which leads me to believe the problem might be elsewhere?? The sound seems to vibrate at a few Hz, and the volume is definitely affected by the volume control.? ?Plugged into my bench supply, it draws 140mA at 13.8V, and the display and menus work fine.

I'm still investigating (I have a DMM and oscilloscope, and I'm normally very good at assembly), but does this sound familiar to anyone???

Thanks!