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Old 05-21-2011, 03:01 PM
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VintagePC VintagePC is offline
Tube bug got me 05/2010
 
Join Date: May 2010
Posts: 535
Looking at your picture, what you'd want to do is as follows. This will ensure you've tested the coils:

1. Disconnect/desolder the ground connection at the lower yellow arrow. (this ensures you test the coils themselves and not an alternate current path - note the other yellow arrow traces through the transformer and also to ground, resulting in two possible paths for the current to flow when you measure any two points in that line.)

2. Measure across the blue arrows.

3. Measure across the red arrows.

4. Reconnect the ground connection from step 1.

It looks like you have resistors in parallel with your coils in the schematic. If that's the case, the resistance you measure should be 1/measurement = 1/(coil resistance)+1/(resistor resistance). Keep in mind the coil will have a fairly low resistance, so the reading is probably only a handful of ohms.

With both resistor values the same, the red and blue measurements should be identical.

If you measure anything different than expected, you'd need to disconnect one lead of the resistor to determine the culprit (coil or resistor)

Last edited by VintagePC; 05-21-2011 at 03:04 PM.
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