Superscan PI

[GeoMax]

The LM337 is used as a current limiter for the audio.

[ZOUjiarui]

[ZOUjiarui]

Ultra scan lm337 I think it is used to stabilize the voltage, I can not see it can control the sound. The original may be a triode.

[ZOUjiarui]

The gold scan is probably closer to it.

[ZOUjiarui]

The gpx5000 seems to have no reference value. I think I'm getting off topic.

[ZOUjiarui]

https://www.geotech1.com/forums/showthread.php?23264-MPP-with-DD-coil-580-uH-and-short-delay

[Alexismex]

[Alexismex]

superscan

[ZOUjiarui]

https://youtu.be/C6ImQPH2zUM
The video shows that the coil is unlikely to reach 2mm

[ZOUjiarui]

The ground coil should not have an exact value.

[ZOUjiarui]

When TX is 0.6mm, the resistance is just around 1.5

[ZOUjiarui]

Sample pulse widths 45uS.

The coil inductance should be 500uH for TX and RX, with a TX resistance of 1.5 ohms, including the cable.

Because of the low pulse rate and wide spacing between 1st and 2nd sample pulses, the unit can be affected by low frequency rf signals and power line noise. The MK2 version has a TX frequency control that can often counteract this. Also the integrator TC is adjustable (response speed) - slower smooths out the noise more.

For best signal on any object, the TX pulse width should be about the same as the decay time of the object signal. A large copper pan could have a decay time considerably longer than 500uS and not give as good a range as a similar size object of less conductive metal.

Ground signals from iron mineralised ground will be strong with a single TX/RX coil, but the Superscan was also designed to use separate TX and RX coils. An outer TX with and inner RX of half the diameter will give much less ground response. Also you can lay a big 10m x 10m TX coil on the ground, and search within it with a 0.5 or 1m RX.

Eric.

Eric Foster says it has a resistance of 1.5.

[ZOUjiarui]

Xtrem Hello, this is too thick, and its resistance is too small.

[Xtrem]

The diameter of a single thread is 1mm, which seems to be different from what Eric Foster said, using thinner thread. Could it be that the wire end of the other coil is more than 1mm?

Wire is more than 1mm, maybe 2,5mm ,i dont remember exact. the coil is very heavy.

[eclipse]

I guess not, but also 1mm is too think perhaps 0.75mm is the correct size. If you take 4 wire 40 meter cable and you connect the wires to form a coil the resistance will need to stay 3-3.5 ohms I guess if it's out of this range you pick thicker or thinner wire but it wouldn't matter so much. Thicker wire - heavier coil.