For sale is reprint of Hickok 539B and 539C Tube Test Data book. Tube Data Book is 84 pages long. General test data section is 23 pages long, Obsolete tube types is 26 pages long, Foreign tube types section is 27 pages.  Real Paper Manual. Quality Printed and Comb Bound. Printed from available copy or scanned from original at 800dpi, restored in Photoshop, Laser printed on premium acid free paper, they will serve for years. Most manuals Include foldout of Circuit Diagram. Cover page printed on Cover Stock.