Vacuum-Tube Voltmeter Model 549
Supreme Instruments Corporation
Mfg.Date:1940 City: Greenwood, MI
Alternating Current supply AC/DC 3V & AC
117.5 Volt
The Supreme 549 multimeter measures:
AC Volts, DC Volts, Ohms, and Milliamps
This vacuum tube voltmeter uses a #6F8G and a #37 tube.
Closed, the oak dovetailed case is 11"x9¾"x5½"
NOTES:
Powered it up and tested it. It measured a 9vdc battery spot on.
Didn’t check ohms because of battery.
The batteries in there are probably from the 60s.
The oak case has damage on one side and a few holes that aren’t supposed to be there.
The case is in pretty good shape otherwise.
The schematic is listed as one of my pics.