NEW
Disassembled From A Rack Assembly But Power Supply Is New

Sorensen
Narrow Range Power Supply
P/N: QSA18-1.9

Input:
 - 105-125 VAC
 - 1.3 A
 - 47-440 Hz

Output:
 - 14-22V DC
Max Current:
 - 2.1 A
 - 1.9 A
 - 1.6 A
 - 1.3 A

 The QSA series are designed for operation on any of three separate, single-phase inputs, the units provide a variety of highly regulated dc outputs. They also offer extremely fast recovery times as well as characteristically low output impedances.

Good selectivity in mounting position is a unique feature. The unit may be end, bottom or side mounted.

In the pictures section (Upper top left )  is a magazine page from an ad in 1966 detailing a bit more about this type of unit.. Understand the page is 50 years old and minor design changes may have taken affect.