I am trying (mostly successful) on resurrecting a Hickok 800A that has been dormant for the last 20 year. After carefully readung all I could on the web (forums, manuals, calibration procedures) I was able to get everything in spec, until I ran into the Balanced Meter Bridge aka - English Control. HP 8901B Operation and Calibration Manual Information for MAJOR changes is also provided for instruments with serial-number prefixes not listed in the above range. Fa HEWLETT PACKARD 99 Washington Street TRANSCONDUCTANCE TUBE TESTER MODEL 539C WARRANTY The Hickok Electrical Instrument Company warrants instruments of its manufacture to be free from defects in material and workmanship for ninety (90) days from the constant calibration indicator which is normally always in circuit. The Find great deals on eBay for hickok tester. Shop with confidence. Skip to main content. eBay Logo: NOS Hickok 3047-3 Calibration Cell Tube Tester NIB. Brand New. $50.00. Buy It Now Ultimate Manual Hickok 600A Tube Tester Operation, Test Data, Much Added Info. Brand New. $19.95. Find great deals on eBay for 8902a. Shop with confidence. Skip to main content. eBay Logo: HP 8902A Measuring Receiver Operation and Calibration Manual. Pre-Owned. $30.00. Buy It Now +$14.35 shipping. MILLER TOOL 8902A NAG1 TORQUE CONVERTER HUB SEAL INSTALLER. Pre-Owned. TESTING THE 12AU7 ON VARIOUS TUBE TESTERS INTRODUCTION published in standard tube manuals. Why? Because manuals assume a set of operating conditions that most testers simply cannot duplicate. In consulting with an expert on Hickok calibration, it was suggested to me that certain HICKOK Ultimate repair, service, maintenance & owner manuals Home; HICKOK Ultimate repair, service, maintenance & owner manuals. 539C operation and service manual 539C Calibration procedure 539C Obsolete Tube Settings Vacuum Tube Testing Vacuum Tubes, Reviewing the Most Popular Hickok Testers Technical Manual TM 11-6625-274-35 dated 30 June 1960 to Chang