Pyramid PS36KX regulated power supply, 12~15 VDC power supply 115 VAC input

Pyramid model PS-36KX regulated power supply. The output is an adjustable 12 to 15 volts DC and the input is 115 volts AC. We've plugged this power supply in and tested it with voltage meter and it produces 12 to 15 volt. The voltage is adjustable with the center knob.

We're not sure what the amperage rating is for this as it isn't marked. Judging from the ammeter, we'd guess it is about 35 amps with 45 amps max.

This is from the estate of a shortwave radio buff and has a label with his radio call letters (we think?).