1 Vintage 4" Tachometer Stroboscope Metal Disc

Description

1 Vintage Tachometer Stroboscope Metal Disc
For Speeds from 600, 720, 900, 1200, 1800, 3600, 4800, 7200, and 14400
"Disc Stands Still" when speed is correct.
Used, estate item. Excellent shape. We belive this is for calibrating a peice of electronic equipment called a Tachometer, possibky for a General Radio Tachometer? It was with a collectrion of stroboscope cards (other listings) for turntable speed calibrating.