- Waltham, Massachusetts, United States
- Jun 2nd
B&K 747 Tube Tester, With Manual & Chart, Tests Accurate, Manuals The 747 is a Dynamic Mutual Conductance tester with complete tube test chart and all manuals included at purchase. For example, if you are looking a bushel basket or tube caddy of "pulls" and boxed tubes, you need the 747. The 747 is the most portable tube tester for field tube testing.