On 21 Jan 2015 at 10:44, Leslie Smith wrote: > Dennis wrote that the first thing that 'dies' is the BFO. > True, because the BFO plate supply is fed thru a 'wopping big' > resistor. Very true, but also remember that the HFO operates, normally, with a plate voltage of 35 VDC at the 250V B+... Ken W7EKB