Ground balance compensation coil

[Ivont]

In IB, does the preamp's reinforcement matter when the coil is concentric and when it is double D. I try to construct a DD in Chinese ACE 250, but discrimination behaves strangely. At a greater distance from the coil and the closer, there is a difference in tone.

[Carl-NC]

In IB, does the preamp's reinforcement matter when the coil is concentric and when it is double D. I try to construct a DD in Chinese ACE 250, but discrimination behaves strangely. At a greater distance from the coil and the closer, there is a difference in tone.

Sorry, I don't understand the question. What do you mean by "reinforcement"?

[Ivont]

Hi Carl. Does it matter how much the signal is reinforced from the reception coil, according to whether the coil is concentric or DD. The amplification of this detector is 47K/100 om = 235. Can I without changing it to use a DD coil.

[Ivont]

The metal detector was original with a concentric coil, I try to put double D.
Here are the parameters of the new: 3.375 MH, 21 ohms - receiving coil,
and 2.251 mH, 4.18 ohms - transmitting a coil.

[Qiaozhi]

Sorry, I don't understand the question. What do you mean by "reinforcement"?

I think he means "amplification".

[Carl-NC]

Hi Carl. Does it matter how much the signal is reinforced from the reception coil, according to whether the coil is concentric or DD. The amplification of this detector is 47K/100 om = 235. Can I without changing it to use a DD coil.

You normally design each coil so that it will work properly with the detector circuit without changing the circuit. So, yes, you can design a DD coil that will work, but you can't just connect any DD coil and expect it to work.

[Ivont]

The soils where it will be used are with impurities of iron, and I plan to leave XL a little less than XC.

[Ivont]

Нищо не стана . Жалко. Как се изчислява фазов ъгъл.

[Ivont]

.

[Ivont]

Hello friends. These formulas, are they valid for LC circuits. Karl, please tell me something. The Q factor of my receiving coil is 11. Is it okay.

[Ivont]

I think he means "amplification".

Hi Qiaozhi. In my case, the phase in the receiving coil moves when adding ferrite. Shouldn't only the amplitude move?

[Carl-NC]

Are you resonating the RX coil? If you are, then don't and see what happens.

[Ivont]

Are you resonating the RX coil? If you are, then don't and see what happens.

Thank you Karl for the advice. At first I tried at 8.2 kilohertz. Q was 8. I tried at a little higher and much lower than the transmitter coil. In this case, the discriminating program worked at 6 kHz on the receiver and 8.2 kHz on the transmitter. Currently the transmitter is at 11 kHz but I haven't measured what's happening with the oscilloscope. The receiver coil is at 10 kHz. Because I bought a big 3D printer, and made a housing, on which I applied graphite on the inside. Now the capacitance shows 750 pF.