The easiest way to give a listen for CHU 7850 kHz on a QCX-40 would be to store 7850 in one of the rig's Frequency Presets, and then transfer that to, say, VFO A.
Don't forget to add your cw offset for USB reception, so store 7850.7 etc, since CHU heavily attenuates its LSB. Also ensure you're set up for CW, as opposed to CW-R.
Hw nw ?
Tnx es 72 / 73,
Bill, N4QA