Hickok 533 Restoration - Inviting Feedback

[Geoff]

I went through this tonight, checking resistors and replacing the 0.1 mfd tubular capacitor. Amazingly most of the resistors are within tolerance, even the carbon comps.

I disconnected the wires going to the meter and got 80 ohms so that appears to be fine.

But I did find something interesting. There is an 8,500 ohm resistor installed. There is no 8,500 ohm resistor in the parts list. Here it is:





Not sure what it goes to since it is not called out anywhere. The only thing I can think of is I've been able to trace out all of the resistors but cannot find R6 (6K resistor). Could this 8,500 ohm resistor be a substitute for the 6K? And what is the band around the 8,500 ohm resistor. It has no affect on resistance when moving it back and forth.

I also noticed that there is a 330K resistor installed where there should be a 500K (R10):



Both of these mystery resistors appear to be original. Anyone have any thoughts on these?

And one last thing. I want to make sure I am reading the two mica capacitor color codes correctly. I am using the color coding chart found here from Radio Daze:

http://www.radiohistoria.fi/yabbfile...2_edited-5.jpg

This one I believe is 470 pF (0.00047 uF). This is most likely C2 (0.0005 uF, 1000V) but the green dot indicates that it is only rated for 500V.



This one I believe is 240 pF (0.00024 uF). However, the schemamtic does not call out for this capacitor. It should be C3 (0.0027 uF, 1000V). Again, the green dot indicates it is only rated at 500V.



Any feedback on what I found would be greatly appreciated. The schematic is located here:

http://antiqueradios.com/gallery/v/t...matic.pdf.html

Click "Download document"

- Geoff