24-12-2016, 05:34 PM
Hi Trevor,
All the valves in this set have 6.3volt heaters and are fed from a winding on the mains transformer. The primary functions as an auto transformer with the 250 volt upper tapping supplying the HT rectifier. There is an additional heater winding with taps for 2, 4 and 6.3 volts for the CRT.
The attachment shows the circuit diagram of the similar Regentone BIG12 Mark 2. Like the Defiant 1250 under discussion the BIG12mk2 has an HT smoothing choke and also the electric picture shifet controls.
Geordie McBoyne.
All the valves in this set have 6.3volt heaters and are fed from a winding on the mains transformer. The primary functions as an auto transformer with the 250 volt upper tapping supplying the HT rectifier. There is an additional heater winding with taps for 2, 4 and 6.3 volts for the CRT.
The attachment shows the circuit diagram of the similar Regentone BIG12 Mark 2. Like the Defiant 1250 under discussion the BIG12mk2 has an HT smoothing choke and also the electric picture shifet controls.
Geordie McBoyne.
