Hickok 538A Dynamic Mutual Conductance Professional Tube Tester and Analyzer

Description

Here for your inspection is this very rare Hickok 538A Mutual conductance tube tester. It came to me with a bad main meter. So, I had a new factory
Simpson
meter made and I installed it. This unit works well but will need calibration. I have paperwork on the meter as well. I have replaced some components like capacitors and one resistor but I ran out of time. I'm only asking for what I have into this--It cost me 500.00 to get it here and 300.00 for the meter. I cleaned as much as I could but it will need more. All switches work and all
functions
work. This unit is
different
then any other Hickok I have seen, in that the main meter is NOT wired to P7, it has a smaller meter in the upper right corner and P7 operates that meter. You see, you will set the small meter with the line adjust to 100 volts, while pressing P4 you will readjust to maintain 100 volts. This is how they take care of
voltage
drop when
under
test. As you can see from the pictures--I am testing a 6L6 with gm of 5700---this unit comes so close I was
amazed!
It comes with a copy of the original manual. Outside case is a bit rough but I tried to cover all angles. Please feel free to ask questions. Thank you for looking.