Tesoro's coils cables

[Max]

Hi all,
I have a question about cabling for tesoro coils...cause I get a strange behaviour with a small audio cable connected to my DD coil for bandido.

Coil is working ok.
Problem is when I move cable...I get response in the audio too !

What's wrong ???
It's a two coaxial like in audio works...e.g. hearphones...two shields I connected at same point to gnd.
Need I a bigger cable ????? Like in PIs ????

Can't understand. Any suggestion welcome.

Best regards,
Max

[Satel]

Hi all,
I have a question about cabling for tesoro coils...cause I get a strange behaviour with a small audio cable connected to my DD coil for bandido.

Coil is working ok.
Problem is when I move cable...I get response in the audio too !

What's wrong ???
It's a two coaxial like in audio works...e.g. hearphones...two shields I connected at same point to gnd.
Need I a bigger cable ????? Like in PIs ????

Can't understand. Any suggestion welcome.

Best regards,
Max

Hi Max
In my original Tesoro coil (with homemade MD) same problem. In original coil every wire shielded and the all shielded wires put in common shield.
Satel

[Qiaozhi]

Hi all,
I have a question about cabling for tesoro coils...cause I get a strange behaviour with a small audio cable connected to my DD coil for bandido.

Coil is working ok.
Problem is when I move cable...I get response in the audio too !

What's wrong ???
It's a two coaxial like in audio works...e.g. hearphones...two shields I connected at same point to gnd.
Need I a bigger cable ????? Like in PIs ????

Can't understand. Any suggestion welcome.

Best regards,
Max

See attached diagram of Tesoro wiring. Notice that the screen is actually one wire of the transmitter coil, which must be connected to ground, and is connected to the violet (purple) wire of the receive coil within the search head. I have also noticed that you need to ground the body of the coil connector (if this is the metallic type) to prevent any instability.

[Max]

See attached diagram of Tesoro wiring. Notice that the screen is actually one wire of the transmitter coil, which must be connected to ground, and is connected to the violet (purple) wire of the receive coil within the search head. I have also noticed that you need to ground the body of the coil connector (if this is the metallic type) to prevent any instability.

Hi Qiaozhi,
I've connected first inner wire (white) to RX...then second wire (red) to TX free leads. Internally connected rx-tx other wires to a common gnd pad in the search head...then also the two shields with separate cables to same gnd pad. I have 3 wires that go to connector:
- red (tx)
- white (rx)
- shield of two (gnd)
Metallic part of connector connected to gnd too.
Get 1mV pk-pk of nulling this way.

Only difference I can see is that in original coil there are two wires for gnd (one for tx -shield- and one for rx -violet-) as I can see from wiring diagram.

Again...can't understand where the problem is.

Maybe capacitance ??? Big headhacke !

Best regards,
Max

[Max]

Hi Max
In my original Tesoro coil (with homemade MD) same problem. In original coil every wire shielded and the all shielded wires put in common shield.
Satel

Hi Satel,
seems like what I've done. But I have only two shields as gnd wire...

Really don't know what's wrong...other strange thing is that with concentric-coplanar coil I haven't this behaviour.

Only with DD-coil it showed !

Best regards,
Max

[Satel]

Hi Max
Sorry for bad picture (I cant get better) and drawing, but maybe eny help from them.The original tesoro coil cable look likes in drawing (it was hard to see, but I think, I see right), non insulated wire connected to pin 5.

Best regards
Satel

Hi Satel,
seems like what I've done. But I have only two shields as gnd wire...

Really don't know what's wrong...other strange thing is that with concentric-coplanar coil I haven't this behaviour.

Only with DD-coil it showed !

Best regards,
Max

[Qiaozhi]

Hi Qiaozhi,
I've connected first inner wire (white) to RX...then second wire (red) to TX free leads. Internally connected rx-tx other wires to a common gnd pad in the search head...then also the two shields with separate cables to same gnd pad. I have 3 wires that go to connector:
- red (tx)
- white (rx)
- shield of two (gnd)
Metallic part of connector connected to gnd too.
Get 1mV pk-pk of nulling this way.

Only difference I can see is that in original coil there are two wires for gnd (one for tx -shield- and one for rx -violet-) as I can see from wiring diagram.

Again...can't understand where the problem is.

Maybe capacitance ??? Big headhacke !

Best regards,
Max

Hi Max,

The only thing I can suggest is to use a different screened cable. Try one where the screen is braided, as with the original Tesoro coil. It seems to me that the cable you are using is microphonic.
In the next couple of weeks I am planning to make a double-D coil for comparison against my Tesoro concentric. I will let you know if I have any problems.

[Max]

Hi Max,

The only thing I can suggest is to use a different screened cable. Try one where the screen is braided, as with the original Tesoro coil. It seems to me that the cable you are using is microphonic.
In the next couple of weeks I am planning to make a double-D coil for comparison against my Tesoro concentric. I will let you know if I have any problems.

Hi Qiaozhi,
you are right on cable. I've tested another similar but different for audio works too and now seems it's ok.
It sounds just moving the last 10cms or so at the end near the coil, but not in the middle or near the connector. So seems it's ok cause sound is due maybe only to coupling between nearest portions of wires and coil loops.
With the other cable I had instead problems when moving in every part of it...think that it has a poor shield and is definitely not a quality cable.
I've tested on workbench only.
So I think that with a pole-mounting I've everithing working ok...also if I plan to hip-mount detector unit and not fix it on the pole too.

Best regards,
Max