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Old 27th December 2010, 10:59 PM   #5591
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The higher than spec reading may have been an artifact of the coil heating up and glowing like a valve filament
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Old 27th December 2010, 11:04 PM   #5592
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Nah, I touched it very fast, only as long as it took to show and I did it at the other end of the leads on the RCAs. 19.16 Ohm but I say 19 Ohm because of the interconnect and arm wires. Then again if it glowed, now I will have tube tone for free, and low noise. I could even manage the No noise spec if I burned it. But its alive and kicking.
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Old 27th December 2010, 11:39 PM   #5593
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The modern DVMs have high internal impedance in resistance mode I trust. Very little current to give. But what about using a known resistor, measured on same DVM, like 2k2 in series and subtracting it from the total resistor+cart measurement. That should protect any cart from any possibly strong DVM. But the DVM must reliably show the correct extra Ohm relatively to the 2k2 bulk. Must be a rather good one for tolerance spec.
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Old 27th December 2010, 11:47 PM   #5594
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I need to look up the spec on my Fluke 8840A. I suppose it should be able to measure it.
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Old 28th December 2010, 12:13 AM   #5595
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What? A desktop Fluke? Must be crazily accurate.
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Old 28th December 2010, 12:24 AM   #5596
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It is the only calibrated instrument I have. I think I can do a 4 wire measurement with the resistor to buffer the current. However, the 2 wire only passes 1mA and can be offset for lead resistance.

I measure 19.22R on the Right and 17.86R on the left channel. It is repeatable. I did this on the new one fresh out of the bx.
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Old 28th December 2010, 12:29 AM   #5597
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Don't do a Kelvin, no need. It surely takes 220R load then. Denon, I come to Japan for Kill Bill 3! Thanks Scott.
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Old 28th December 2010, 12:31 AM   #5598
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Now I am curious to the sound of it with it properly loaded. I may have to pull the Pheonix out and try it.
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Old 28th December 2010, 12:34 AM   #5599
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use a 1.5V battery and wire it to a 1k0 resistor in series with the MC/MM coil.
The 1k0 will limit the coil current to <1mA and the power dissipated in a 10r coil would be ~10uW and in a 100r coil ~0.1mW
The coil cannot glow red hot. It might run slightly warm !

Now read the voltage across the coil and across the resistor.
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Old 28th December 2010, 12:40 AM   #5600
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No need for protection resistors any more since Scott and I we did not wimp out.
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