Q-meter

[Achiles]

Would it work for us.
http://electroraggio.com/fs_files/us...IOS/Qmetro.GIF

[jmaf]

Fala velhinho. By just looking(not familiar with the circuit) that circuit will sum the rectified voltages passing through the resonant pair in the coil + capacitor test circuit. The JFET will buffer your input and pass through a signal with similar amplitude to that the LC filter let pass. The band pass energy is then accumulated (rectified + stored in capacitors).

You probably then divide the input voltage / accumulated output voltage to find the Q. The more precise the LC pair is, the smaller band of voltages it'll let acumulate in c6 and c7.

My OCD complains that he wrongly calls JAF1's inductance impedance

Edit: less voltages => smaller band of voltages

[Achiles]

What?can it be used for Q pickup measument

[jmaf]

What?can it be used for Q pickup measument

I'm not sure about that circuit.

Have you tried one of these? 380193 - Passive Component LCR Meter

[FunkyKikuchiyo]

What?can it be used for Q pickup measument

Here's a hint: "Fala velhinho" backwards is "Ohnihlev alaf"

[David Schwab]

Have you tried one of these? 380193 - Passive Component LCR Meter

That's the one to use for pickups.

[Joe Gwinn]

Would it work for us.
http://electroraggio.com/fs_files/us...IOS/Qmetro.GIF

This is intended for use at RF, not audio. The giveaway is that C1 and C2 are 6 pF each, far too low for the circuit to work at say 10 KHz.