Superscan PI

[ZOUjiarui]

The diode next to the irf740 is completely redundant, it controls power, but the PCB layout keeps it running at maximum power

[eclipse]

I have one of these rare Superscans with me right now. What I'm more interested in is not the board but the coil options.
I have one square 1x1 cable for mono operation, now I know these had large 10x10 meter cable for TX and RX was a small coil. The parameters of these I can only guess.
Perhaps the RX coil had 400-600uH 15-30 ohms with or without a damping resistor inside. TX coil could be /maybe/ 2-3 turns of 0.50mm - 0.75 wire with other shielding perhaps some damping resistor too.
I'm rather busy but If I have time with need to test this but I think those Superscans with the TX/RX arrangement could work with a normal DD coil /Minelab for example/

[ZOUjiarui]

I tried to email the seller in Greece requesting a test video. I get a reply that the recipient's mailbox is full.

[eclipse]

Measured the original 1x1 coil - here are the specs: 550uH, 2.1 Ohms.

[Xtrem]

I have the original 10mx10m Coil , it is 870μH , 4 turns, 3,2Ω

[ZOUjiarui]

I have the original 10mx10m Coil , it is 870μH , 4 turns, 3,2Ω

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?

[ZOUjiarui]

I sent a message to the Greek producer via mobile phone, hoping to get a reply.

[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.

[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.

[ZOUjiarui]

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

[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]

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

[ZOUjiarui]

The ground coil should not have an exact value.

[ZOUjiarui]

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

[Alexismex]

superscan