There is an easy way to pre-tune the BFO for SSB. Fortunately Mil and Aero HF are all on whole-number frequencies such as 8.867000MHz not like hams that drift around. The BFO is there to replace the carrier, so you tune to an AM broadcast station (or WWV) then turn the BFO on and turn the control for 'zero beat' - that point where the tone gets lower and lower until it disappears and then starts rising again. Now put a dob of paint or nail polish on the centre of the knob or thumbwheel. Now when you tune to a station who is tuned to x.xxx000MHz then the BFO with the knob in the centre should be right on frequency!