Hickok 533 Restoration - Inviting Feedback

[Geoff]

I was reading the calibration procedure for the Hickok 600A written by Daniel Schoo and I also watched the 2 YouTube videos by Bob Anderson entitled “Hickok 600A Restoration”. In Daniel Shoo’s article it states:

MUTUAL CONDUCTANCE READING TEST
Verify that the panel switches are set up to the conditions as given in PREPARATION at the beginning of this section, (JR 5347-2) FILAMENT at 6.3 volts. Set the BIAS and the ENGLISH controls to zero. Rotate the ENGLISH control clockwise to the orange dot near number 73.

For the following mutual conductance test you will need to set up an isolated current limited source of AC voltage. Use the setup drawing in figure 1 to connect the equipment to the tester. Be careful because improper connection can cause serious damage. Connect the source to pins 8 and 3 of the octal socket. If the main meter deflects downward instead of up when you perform the test, swap the connections to pins 8 and 3. Measure the voltage source directly across the secondary of the isolation transformer. Do not use a shunt resistor across the meter.


FIGURE 1

Push P4 and slowly adjust the voltage source up to exactly 50.0 volts. Observe the reading on the tester meter. The correct reading is 2000 micromhos plus or minus one small division on the 3000 scale. It may be slightly worse depending on the quality of the ENGLISH control. After taking the reading set the voltage back to zero and release P4.

So the directions state Set the BIAS and the ENGLISH controls to zero. Rotate the ENGLISH control clockwise to the orange dot near number 73. Those correspond to the different scales (3000, 6000, 15000). #My 533 does not have the orange dot near number 73 on the ENGLISH dial, but it does have a separate switch for the scales (3000, 6000, 15000). #Would I be correct in assuming that I could set the ENGLISH dial (and BIAS) to zero, set the range switch to 3000, apply the 50V as detailed in the procedure, and expect a reading of 2000 micromhos (assuming everything else is working properly)? #If it was not at 2000 I would follow the Control Alignment Procedure as detailed in the article and demonstrated in the YouTube video.

I think it should work but I’d like to bounce off you guys as a sanity check before I try it.

Thanks,
Geoff