Voodoo Main Discussion

[zakari]

hi 6666
i am thinking you must connect the end of the red wire to starting of the blue wire not the green.
in this case that is difficult to nulling the concentric coil and you cant add or reduce laps the green wire for best inductance and best nulling .

best regard
zakari

[6666]

Here is a slight variation on the concentric coil it has a small loop for fine tuning the null.

[MartyJ1963]

Hi George, I forgot to ask you in my last post,,What would be the best cable to use for this coil setup please? Thanks, Marty.

[Qiaozhi]

Just curious, but could a circular dual field TX coil be used with the RX? And if so, would the Dual field coil ( like a spider coil) still need two damping resistors? Thanks, Regards, Marty.

I don't think you could have a dual-field coil that has a concentric RX loop. At least I've never seen one.

[MartyJ1963]

Thanks George,,,Sorry, About the Battery charger pcb, I'd realised what I'd written only after I wrote it,,I meant just to say I didn't want the batteries in the enclosure,,my bad,,Lol. I wanted to start the power supply section 2 nights ago but some repairs we've been doing to do the house were overlooked so I'll be startng tomorrow now. Just curious, but could a circular dual field TX coil be used with the RX? And if so, would the Dual field coil ( like a spider coil) still need two damping resistors? Thanks, Regards, Marty.

[Qiaozhi]

George, have you tried hybrid mode on the wet sands of the beach?

I had intended to do that, but I live a long way from the nearest beach and Covid restrictions prevented me from going there. However, the PI mode will definitely work in the wet sands. Since an audio response depends on both the PI and DISC channels responding at the same time, I have every confidence that there won't be a problem. Remember that false signals from a VLF detector in wet sand are caused by the GEB channel, not the DISC channel.

[Qiaozhi]

I don't intend including the Battery charge board and battery in the same enclosure ...

The battery charger not intended to fit in the detector enclosure. It is an external unit.

[lamoiz]

George, have you tried hybrid mode on the wet sands of the beach?

[MartyJ1963]

Hi Alec,,,I have a plastic enclosure that I may use but I haven't fully decided on whether to use it or not yet. I posted a pic of it with the dimensions. It is 50mm deep but if I decide to use it I may cut the top off it to make it around 35mm deep or so that there's just a bit of clearance on the tallest components. The lid fits snuggly over the bottom part. I don't intend including the Battery charge board and battery in the same enclosure as I want to be able to use 18650 batteries and change them as they deplete in the field. This enclosure is only a 'Maybe' at the moment. The handle is going to be made in 2 parts with a hollow centre to accept the LCD/Menu button cable and will join to the top part of the enclosure that will slide directly over the detector shaft. I have some other ideas so I won't know which enclosure I will decide on until I reach the LCD Section of the build. I'm enjoying your 'HammerHead' build videos!,,Do you have the Gerber files for that particular pcb you're building on the Video? With the Mirage being my favourite detector I've always wanted to tackle the HammerHead and the Crossbow to add to my collection. Stay safe Alec, Regards, Marty.

[surfdetector]

Thank you George. I just have to calculate the wire length for the cable that needs to go from the pcb/enclosure, along the shaft and up the handle, before I build the LCD/Button section and also have to decide whether I'm using plugs for the cable or not. Thanks again, Marty.

Marty,
What sort of enclosure are you using for the LCD and the push buttons?

[lamoiz]

i have more than 1000 uf .. i await delivery. in the meantime, I'm working on the sensor.

[MartyJ1963]

Thank you George. I just have to calculate the wire length for the cable that needs to go from the pcb/enclosure, along the shaft and up the handle, before I build the LCD/Button section and also have to decide whether I'm using plugs for the cable or not. Thanks again, Marty.

[Qiaozhi]

Hiya George,,,Can a LM555CN or a 7555IPAZ be used in lace of the NE555 please? If not, is an NE555P ok to use instead of NE555N? Also can a HEF40666 be used instead of 4066BP? Thanks, Marty.

Any of those will be OK.

[MartyJ1963]

Hiya George,,,Can a LM555CN or a 7555IPAZ be used in lace of the NE555 please? If not, is an NE555P ok to use instead of NE555N? Also can a HEF40666 be used instead of 4066BP? Thanks, Marty.

[lamoiz]

voila, the power section is done, I have adapted some voltage on the 100uf capa I lack one 25v to do. So I got a 16v after the 7805 ... it should work ... later on, after the aperitif