# Pickup phase/polarity testing

Discussion in 'Pickups & Electronics [BG]' started by finetops, Feb 5, 2017.

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1. ### finetops

May 28, 2013
Hi Guys,

So there's this trick for determining the electric phase or polarity of your PUP, right? You attach the voltmeter to the lead wires and place a metal object (screwdriver) on the top of a pole piece and if the momentary volt reading is +, your red voltmeter probe is attached to the + phase and vice versa.

1. Just in order to visually understand what's going on inside the PUP, does the + wire mark the beginning (center) of the coil or the end (outside)?

2. What about Precision type split coils? Sometimes the connecting wire between the coils is completely insulated so you can't attach a probe, does it make any sense to measure the sum of both coils? Are they as a rule in phase or out of?

2. ### megafiddle

May 25, 2011
To be more precise, the meter will indicate one polarity reading when the screwdriver tip is touched to the magnet pole, and the opposite polarity when the screwdriver tip is pulled away.

I don't know if there is any standard for which terminal is considered "positive" with such a test; the important thing is that a consistant method is used to identify the terminals.

1. A wire identified as "+" could be either the start or finish end of the coil winding. What's important is the direction of the winding. So for example, if the wire in question was the start end, and proceeded outward in a clockwise direction, it would have the same polarity as a wire that was the finish end and proceeded inward in a clockwise direction. This assumes that the magnet polarity is the same.

Both winding direction and magnet polarity are involved in the phase of the pickup. Both of these things would affect whether the "+" wire was the start (inside) or finish (outside) end.

2. You can just measure the two wires coming from the pickup pair assembly and look at the sum. Each half will produce an indication of it's own phase and both halves should be the same.

You probably would want use a pole on the half being tested that is furthest from the other half (don't use the poles where the halves overlap).

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