TUBE SET TESTER model 504-A manufactured by Supreme Instruments Corp.
This push button set tester was produced in three model versions, the 504, 504-A, and 504-B.
This series Supreme tube tester has a built in roll chart for tube data. The front panel has painted lines from the chart to the corresponding controls for easy tube set up.
This tube tester also measures DC, ohms, milliamps, amps, and capacitors
* Source: Steve΄s Supreme Instruments CollectionSupreme Instruments Corp. Greenwood Mississippi 1926 - 1956