Wireless Set No. 52 Canadian - Project

[Bruce MacMillan]

Looking at the xfmr secondary the centre tap goes to ground. Unplug the OZ4 and measure resistance from pins 3 & 5 to ground. This will include the resistance of the chokes. I wouldn't think there should be a lot of difference. If there is then disconnect the chokes and measure the voltage on the xfmr secondary to see if different. Hopefully not a shorted winding.

The DC side is separate from the AC side with the exception of R35A and R35B loading the vibrator winding to ground. The schematic shows each is 300R 5%. A good vibrator has no effect when running with AC and that is why it can be left in situ.

The primary side of this psu is almost identical to the VP-3 psu used with the Marconi CSR5 receiver. Vibrator used is nonsynchronous 115 cycle p/n 111-131.