Carnhil VTB9045 (10468) Microphone Input transformer. What ballpark resistance should I be seeing across XLR pins 2 and 3?

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777funk

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I'm getting around 30 ohms and it's dropping my phantom power from 52VDC to 40VDC (via a pair of 6.8k resistors feeding XLR pin 2 and 3). Is 30 ohms a normal input resistance on this transformer?
 

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emrr

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yes. I assume your mic load is what's actually dropping your voltage, also normal.
 

emrr

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The transformer doesn't load if connected correctly. You're sending identical 52V to both sides of a floating winding, there's no load. Impossible to know from the evidence.
 

777funk

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The transformer doesn't load if connected correctly. You're sending identical 52V to both sides of a floating winding, there's no load. Impossible to know from the evidence.
Yes you're right. I hadn't looked at a mic input transformer schematic in a while. Not sure why I have a voltage drop without a mic connected. Will need to investigate a bit.
 
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