Wireless Set No. 52 Canadian - Project

[David Dunlop]

When my second CPP-2 Power Supply arrived, I did a preliminary inspection and cleaning, tested it for working status, and that was it. I still have not yet performed a detail cleaning, but that will come in time. The important thing at this point was to ensure a close match in output between the two units. These power supplies come with a 6-position rotary switch that allows the supply to be set at various points between roughly 10 and 15 Volts DC. I was quite pleased I could get both of them sync’d at 13.5 Volts DC output to start.

The first photo has my original CPP-2 running with the amber indicator lamp and the new one with the red lamp. The second photo shows the input voltage at the Supply Unit after a short warm up.

The third photo shows the meter on the Receiver set to LT and reading a steady 12.0 Volts DC.

In the fourth photo, I have set the metering up to read the HT1 voltage being delivered to the Sender. This comes exclusively from the MG1A Dynamotor. Under a normal load condition in the Sender (all valves in place and not transmitting) this value would be 300 Volts DC. As you can see the meter reads a steady 160 Volts DC, which for the purposes of reading HT1 values, gets a ‘ x 2 Factor’ applied giving a no load value of 320 Volts DC, which is within the specified parameters in the manual.

The last photo is just a look at the full 52-Set idling with no load and its Supply Unit running perfectly in Send Mode. Something of a milestone moment after sitting idle for a number of decades.

Since the electrical testing I performed a few weeks ago showed no red flags up to the V7A (813) Power Amplifier, I am now going to recheck the Voltage Regulator V6A, and three 6V6G’s (V5A, V5B and V5C), the Master Oscillator Doubler, Amplifier Doubler and Intermediate Power Amplifier respectively, reinstall them in the Sender and run the Supply Unit again with them in place. Hopefully, there will be no surprises.


David