Precision Tube Tester 612 and 614 Operating Instructions Sorry, this product cannot be purchased. $7.99 Category: Precision Apparatus Company Related products Precision Tube Tester 620 Operating Manual $8.99 Read more Precision Apparatus Series 40 AC-DC Multi-Range Test Set Manual $5.99 Read more Precision Tube Test Data for 10-60 Tester $9.99 Read more Precision Tube Tester Model 660 Operating Instructions with Tube DataOpens in a new window or tab $13.99 Read more