rulerboyz
AK Member
Bias current stuck at 0 on left side (solved)
I've run into another bias stuck at zero situation while trying to set the bias on the Kenwood KR-4140. The right side is holding it's bias at 10mv, but when I test the voltage drop across the output resistors on the left side I get a reading that quickly drops to zero after I apply the meter leads. I tried comparing the voltage drops across other resistors, diodes and collector-emitter of the neighboring transistors and right and left seem pretty close. The collector-emitter voltages for the power transistors are all close to 25V each.
Is it possible that this is a bad trimpot? Before I had the dim light bulb tester I did have that cooking resistor problem which might have taken a toll on the trimpot. Any way to test to see if a pot is still good?
I've run into another bias stuck at zero situation while trying to set the bias on the Kenwood KR-4140. The right side is holding it's bias at 10mv, but when I test the voltage drop across the output resistors on the left side I get a reading that quickly drops to zero after I apply the meter leads. I tried comparing the voltage drops across other resistors, diodes and collector-emitter of the neighboring transistors and right and left seem pretty close. The collector-emitter voltages for the power transistors are all close to 25V each.
Is it possible that this is a bad trimpot? Before I had the dim light bulb tester I did have that cooking resistor problem which might have taken a toll on the trimpot. Any way to test to see if a pot is still good?
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