Hi NWM
This KB 279 is mains driven not battery, it has a full isolating mains transformer with three 4 volt outputs (heaters for rectifier, op pentode, & RF and detector valves) and a centre tapped HT winding giving a massive 775 volts AC. I dont know yet what the final rectified HT voltage will be but I suspect it will probably be around 500v DC on the rectifier cathode and 250 to 275v by the time it has been dropped by the 2.3k ohm speaker field coil.
When I come to power it up I will be treating it with some respect.
This is one of the reasons I am planning to use two 4uF 630v polyester capacitors rather than an 8uf electrolytic as the main smoothing capacitor.
Mike
This KB 279 is mains driven not battery, it has a full isolating mains transformer with three 4 volt outputs (heaters for rectifier, op pentode, & RF and detector valves) and a centre tapped HT winding giving a massive 775 volts AC. I dont know yet what the final rectified HT voltage will be but I suspect it will probably be around 500v DC on the rectifier cathode and 250 to 275v by the time it has been dropped by the 2.3k ohm speaker field coil.
When I come to power it up I will be treating it with some respect.
This is one of the reasons I am planning to use two 4uF 630v polyester capacitors rather than an 8uf electrolytic as the main smoothing capacitor.
Mike
