Precision Tube Tester 612 and 614 Operating Instructions Sorry, this product cannot be purchased. $7.99 Category: Precision Apparatus Company Related products Precision Apparatus EV-20 Vacuum Tube Multi-Meter Manual Read more Precision Tube Test Data for 612 614 620 654 Tube Testers $10.99 Read more Precision Tube Test Data for 10-60 Tester $9.99 Read more Precision Tube Test Data for 10-12 10-15 10-20 10-22 10-54 Tube Testers 2-1-1976 $9.99 Read more