Wireless Set No. 52 Canadian - Project

[David Dunlop]

Backtracking to the Vibrator Supply section of the Supply Unit once more, sorry, I decided to take a long shot at testing its 150 Volt circuit, which I had confirmed earlier had continuity. I was curious to see if any of the Electrolytic Caps in the circuit which had likely shut down over time, might respond to being reformed.

I put the Vibratory Supply back on the bench and pulled the 0Z4A and Vibrator. The positive side of my Heathkit Model PS-3 Variable Voltage Regulated Power Supply was connected to Pin 3 of PL9A and the Negative side to Pin 2. This supply is capable of running 0 to 500 Volts DC and monitoring 0 to 300 Milliamps.

Over the course of about an hour and a half, I slowly increased the voltage level in about 25 volt stages while watching the amperage readings to see if and when they would stabilize. They finally did at the 175 Volt mark.

After reinstalling the 0Z4A and Vibrator, I reinserted the Vibrator Supply in the Supply Unit in the 52-Set and turned on my CPP-2 Power Supply. This supply has a seven stop rotary switch that increased the output voltage in steps. Interestingly, the first three steps are: (1) 12.0 Volts DC, (2) 12.75 Volts DC and (3) 13.75 Volts DC. I set the CPP-2 to the third position and switched on the 52-Set. The LT reading on the Receiver Meter went straight to 12 Volts. As I was changing the Meter reading to the HT Option, the Receiver came on to WWV Colorado at 5.00 MC and the HT reading was setting in at 155 Volts. Slightly high but a lot nicer to see than the earlier zero value.

I did not bother checking any higher CPP-2 outputs. 12 Volts DC is the rated voltage level for all the valve filaments in the set. Positions (4) to (7), increase regularly to 20 Volts and I do not want to risk damage to my limited supply of spare vales at this point in time.

Suffice it to say, I am quite happy the Vibrator Supply is back up and running again and it has reminded me to be certain to firw up the Remote Receiver and its Supply this weekend to keep it operating and happy.


David