A bit further forward I suppose. Exactly the same, for 2153 and original,
audible low level oscillator noise , 10 seconds or so after switch off
presumably coming down from ultrasonic and dropping in pitch over a couple
of minutes while there is HV in the main caps. And +/-0.5V on the main rail
caps transfered across the Tx from the startup pulses, instead of the +/-60V
or so . But no sustained drive. Next is some monitor of the Tx primary
feedback route to the driver and somehow monitor the osc f, perhaps change
the SM cap is easier, the SMRs measure ok. Any tricks for fooling the driver
into thinking there is more feedback than actual, a battery wired-in?