DIY Pulse Induction Detector (Impulse III)

[Bush]

Coil Works in Progress.
1. 12`` coil foam insert.
2. New coil top & base. Armstrong bucket base & 20 liter oil tub.
3. Base & coil workings
4. Conductive painted shields.
5. 13`` Shield plate Ohms resistance test.
6. 13`` Shield 1.5 AAA battery DC volt test.
7. 8`` shield Ohms test.
8. 1940`s 8`` shield Ohms test.

 

[Bush]

NF 12`` Coil Modified re-build for SDC2300.
Air tested maximum faint signal depth results in mm.
Lead shot fishing sinkers.
0.46 g ... 30 mm
0.9 ... 45
1.5 ... 135
5g ... 190
10 ... 210
46 ... 240
104 ... 270

Results disappointing as no significant depth advantages over the standard OEM 8`` coil.
Conclusion ; Faraday shielding coatings are excessively conductive as predicted ref post Modified SDC2300.
Coil weight 860 grams.
Re-Hash on the cards.

 

[IBGold]

NF 12`` Coil Modified re-build for SDC2300.
Air tested maximum faint signal depth results in mm.
Lead shot fishing sinkers.
0.46 g ... 30 mm
0.9 ... 45
1.5 ... 135
5g ... 190
10 ... 210
46 ... 240
104 ... 270

Results disappointing as no significant depth advantages over the standard OEM 8`` coil.
Conclusion ; Faraday shielding coatings are excessively conductive as predicted ref post Modified SDC2300.
Coil weight 860 grams.
Re-Hash on the cards.

Hi Bush,

What shielding are you using if Graphite based should be 65 to85 ohms per inch resistance.

If using Nickle , Copper or silver based conductive spray that will be your problem.

Regards, Ian.

 

[Bush]

Hi Bush,

What shielding are you using if Graphite based should be 65 to85 ohms per inch resistance.

If using Nickle , Copper or silver based conductive spray that will be your problem.

Regards, Ian.

Hi mate,
The F1A4 coil shield is 0.086 ohms / 1`` that is with the meter set on 2K.
My shields are not a consistent coating from a spay gun applied mixture of carbon / graphite & activated carbon & water base paint but a reading of 0.55 is average of which i think is too conductive but in saying that i have not been able to register a detected target signal of the shields using another 8`` coil testing them with the sdc so unless the new shields are being detected and are not audible and the sdc is identifying a target signal of the shields and reducing this NF 12`` coil sensitivity but maybe not ?
Other factors maybe coming into play like Litz wire coil winding resistance and winding counts ect.
It would take me years to understand the mathematics in these calculations so i just have to best heed to whatever some of the Pros have to offer that may help us all out.
regards.