Hickok Model 540 Dynamic Mutual Conductance Tube Tester Manual Sorry, this product cannot be purchased. $8.99 Category: Hickok Description Description For sale is reprint of Hickok 540 Tube Tester manual. Manual 7 pages long and includes Circuit Diagram. Manual comes with 4 pages of Ballast Tube Data, Part list and Operating Instructions. Manual is dated 1944. Related products Hickok Model 620 Linear Pattern Generator Operating Manual $8.99 Read more Hickok 532 Dynamic Mutual Conductance Tube Tester Manual $9.99 Read more Hickok 752 Tube Tester Complete Manual with Tube Data +CA4 Data $16.49 Read more Hickok Model 691 Heterodyned Marker Adder Operating Manual $9.99 Read more