The first thing that I need to do to refurbish my Hickok 539B Tube Tester is to clean up its appearance. I bought CRC QD Electronic Cleaner. This quick drying and no residue formula should be OK for my purpose. I remove all the buttons to wipe out all the dust and dirty things from the front plate.


The initial impression, not “too dirty” for around 40 years old stuff but dirty is dirty, period. Some of the buttons removed to simplify the cleaning process.


Cleaning process completed. Well, not too clean but for the first stage, this should be more than enough. I’m gonna buy some more cleaner to make it even more shiny.


The meter seemed OK in terms of the appearance. I think the function also still OK.


The bias meter also looked good. This bias meter is one of the special features of the Hickok 539 series.


Another special feature is the dedicated AC Volt Meter. The line usually will sag a little bit when testing and with this dedicated meter, we can adjust if any sag is detected during the measurement. The sag will affect the measurement for sure.


The roll chart is smooth and some buttons from P1-P7 could be used depends on our needs.


Another special feature is the noise test. We can use special headphone to check whether your tube is noisy or not. Two bulbs from Hickok also used. One if #81 for fuse and the other is NE-51 (110V, 1/25W) Neon for shorts. I think the power (pilot) indicator is #49.


The shunt and filament voltage selector. Hickok 539B support from 0.6 to 117V filament, also for ballast tube.


The signal selector consists of 6 types, from 600-60000 micromhos. Also selector for testing rectifier and VR tube.


Short test selector. The combination from 1-5 will create a simple matrix to identify the short position. Must check the manual book to understand more. While the position from A-E is used for leakage test. Details explained in the manual.


That’s all folks. I will continue with the inside part exploration later (don’t know when).