WHITES DUAL FIELD COIL

[6666]

Dave


take your cat 6 cable and wind it into a circle with several turns.
You now have two ends of the cable with wires at each end.

The cable contains several twisted pairs.
Each pair has a colored wire plus a white wire.
For example if you have 6 pairs that gives you 12 individual wires.

The ends of the colored wires are easy to identify,

you now solder the end of one wire to the end of another wire, so they are all soldered end to end IN SERIES to make one continuous wire. All going in same direction to make a coil.

For example if you have only 4 wires, you solder the end of the blue wire to the end of a white wire, then solder the OTHER end of that white wire to the end of the green wire and the OTHER end of that green wire to the end of a white wire , so one end of the coil is the blue wire and the other end of the coil is the white wire.


blue0---------------------------0white 0----------------------0green0----------------------0white0--------------0

http://www.metdet.ru/korsina2_files/image005.jpg

[daverave]

Hi KT315....thanks for the diagrams which have helped me...can you connect to any wires as long that they are not the same colour ????

[greylourie]

i received my cat6 wire today and i just want to know if i have to solder the six wires together to the same wire colours on each end of the coil.... then use shrink wrap on the wires.

daverave. Imagine you have wound a coil with 16 turns. Now take some side-cutters and cut through those 16 turns. What are you left with ? How would YOU rejoin and splice it back together to make it a 16 turn coil again ???? The link kt315 has given you, and the links from Jose and 6666 on this thread explain this. Why not give us a drawing in an attachment, showing how you think the wires should be spliced.

[kt315]

look on a table and pics here http://www.metdet.ru/korsina2.htm

[kt315]

NOT. solder a wire of one color to a wire of another color.

[daverave]

i received my cat6 wire today and i just want to know if i have to solder the six wires together to the same wire colours on each end of the coil.... then use shrink wrap on the wires.

[daverave]

daverave, I have been following this thread. I hope you dont mind, but I will try to explain where I think you are missing the point with this cat5 coil... Jose found a way to make an expedient coil with material that was readily to hand. Inside the cat5 cable that Jose uses, are 4 pairs of pvc insulated wire. If you take the "cable" and make two turns as described.... You now have 4 pairs wrapped around twice (or however many times you want ). Now if you were to go to each end of your coil you would be presented with 8 wires on each end.... This is really basic stuff. All you have to do is take one wire and make it your start/ beginning. Check continuity with your multimeter or battery and bulb, and find the OTHER end of the wire. Take the other end and join it to another wire, solder and cover with heatshrink. Keep doing this until all you have is two ends. You now have a coil with 16 turns. Its so easy anyone can do it. And the material Jose uses is a very attractive option, readily available in many places around the world. BnQ and TLC in Kent will have this in stock. Often these cables have different coloured pvc insulation for each of the 4 twisted pairs of wires, which makes it even easier to splice together. Basically Jose has come up with a coil that has lower inter-wire capacitance, than one that is wound with normal enamelled winding/magnet wire, and Jose even mentions this in one of his posts. Jose suggests you use the minimum of solder to make these joins. The smaller and neater the joins, the less likely they are to be detected......

If you studied the examples in the attachments made by Jose and 6666, all this would be crystal clear. Look here :

http://www.geotech1.com/forums/showthread.php?20975-WHITES-DUAL-FIELD-COIL&p=179073#post179073

http://www.geotech1.com/forums/showthread.php?20975-WHITES-DUAL-FIELD-COIL&p=179110#post179110

http://www.geotech1.com/forums/showt...132#post179132

Hello greylourie
many thanks for commenting on my post....this is all new to me as in the past ive only used enamelled copper wire...which is very simple and straightforward to wind and is small cluster of wires....i will try this cat6 wire and experiment and see how i get on....i want to make a coil for my hammerhead detector with this cat6 wire...my first coil i used normal copper 30 swg wire but with resin it weighs in at around 500g which is a bit heavy than i wanted....so hopefully this time i can make a bit lighter coil....im really enjoying making my own detectors..and making friends on this forum

[greylourie]

in your photo you show the ends of the wires joined together with heat shrink....why is that ???? ive ordered a 10 metre cat6 cable...can i just wind three 12 inch turns then solder the 8 wires together on each end of the coil ???

daverave, I have been following this thread. I hope you dont mind, but I will try to explain where I think you are missing the point with this cat5 coil... Jose found a way to make an expedient coil with material that was readily to hand. Inside the cat5 cable that Jose uses, are 4 pairs of pvc insulated wire. If you take the "cable" and make two turns as described.... You now have 4 pairs wrapped around twice (or however many times you want ). Now if you were to go to each end of your coil you would be presented with 8 wires on each end.... This is really basic stuff. All you have to do is take one wire and make it your start/ beginning. Check continuity with your multimeter or battery and bulb, and find the OTHER end of the wire. Take the other end and join it to another wire, solder and cover with heatshrink. Keep doing this until all you have is two ends. You now have a coil with 16 turns. Its so easy anyone can do it. And the material Jose uses is a very attractive option, readily available in many places around the world. BnQ and TLC in Kent will have this in stock. Often these cables have different coloured pvc insulation for each of the 4 twisted pairs of wires, which makes it even easier to splice together. Basically Jose has come up with a coil that has lower inter-wire capacitance, than one that is wound with normal enamelled winding/magnet wire, and Jose even mentions this in one of his posts. Jose suggests you use the minimum of solder to make these joins. The smaller and neater the joins, the less likely they are to be detected......

If you studied the examples in the attachments made by Jose and 6666, all this would be crystal clear. Look here :

http://www.geotech1.com/forums/showthread.php?20975-WHITES-DUAL-FIELD-COIL&p=179073#post179073

http://www.geotech1.com/forums/showthread.php?20975-WHITES-DUAL-FIELD-COIL&p=179110#post179110

http://www.geotech1.com/forums/showthread.php?20975-WHITES-DUAL-FIELD-COIL&p=179132#post179132

[Davor]

...It was a lesson well learned about human nature. A mistake like that never happened again.

Dave, I have no idea how people become so bitter over time. Yes, there'll always be certain individuals that will trigger your nerves, but that's certainly not THE essence of you. I'm sure you are much softer on the inside. At least here you are among friends.

[daverave]

Do not know if Cat 6 is better than ordinary insulated wire.
A few years ago when you return to this hobby, I started with the Delta Pulse and coils did with cat5,
It worked very well and since then I use cat5 or cat6.
I will buy regular insulated wire to compare results.
Jose

in your photo you show the ends of the wires joined together with heat shrink....why is that ???? ive ordered a 10 metre cat6 cable...can i just wind three 12 inch turns then solder the 8 wires together on each end of the coil ???

[Jose]

Do not know if Cat 6 is better than ordinary insulated wire.
A few years ago when you return to this hobby, I started with the Delta Pulse and coils did with cat5,
It worked very well and since then I use cat5 or cat6.
I will buy regular insulated wire to compare results.
Jose

[woodbob123]

Dave depth improvement comes in little steps coil, shielding, cable, amp etcetc, its all little steps which add up. once you have your MD working and optimised there are no bigsteps.

[daverave]

Daverave
The photo shows only one of the coils, remember that they are two and are connected in series.
The two coils are constructed identically, the only difference is its diameter.
The inductance of the higher coil is 175 uH and 1.2 ohms.
The inductance of the smaller coil is 100 uH and its resistance is less than 1 ohm.
Connected in series and the coil arranged girl inside the large coil, gives an inductance of 380 uH and 2 ohm
These values are approximate, since my instruments are not accurate.
Do not understand the last question.
You can experiment with a single coil of three turns cat6, and diameter 25 cm (10 inches). You will have 8X3 .. 24 laps and an inductance between 300-350 uH with a resistance of about 1.5 ohms.
Also this type of coil is easy to make and you answer quickly, use less tin solder candidad possible so as not affect their response.
Regards
Jose

im not sure if i want to make a dual field coil and maybe i just stick to single coil design....ive just ordered some cat6 wire pure copper and will experiment once it arraives...is the depth using this wire much better than say using ordinary copper insulated wire ???? i appreciate your help to me all you guys...im a little slow in working things out but hopefully i get there in the end !!!

[Aziz]

Aziz is correct on this matter, as Davor figured out earlier in this thread. The "dual field" approach used on the Fisher Impulse and later by White's has its advantages in saltwater environment use, but in a gold prospecting environment its disadvantages outweigh its advantages.

--Dave J.

************************

Here's a funny piece of history.

Back when we (Fisher) introduced the Impulse, we got an inquiry from a fellow in Australia who had heard some sort of rumor that PI was the hot setup for gold prospecting in hot ground. (This was before the Minelab SD's, I'm guessing that it was Eric's machines that had given rise to this rumor.) The guy wanted us to give him a freebie for field testing, with a promise that he'd publicize the results.

Our marketing guy told him this is a beach & scuba machine, we sell gold machines and the Impulse ain't one, and we simply flat out can't recommend it for gold prospecting. (Even back then, I understood the ground balancing issues relating to PI, having fielded both VLF-style reactively balanced and "early and late timing" balanced prototypes. The Impulse incorporated neither type of ground balancing feature.)

The guy in Australia kept insisting, so our marketing guy finally caved in and sold him one for half price on the condition that he give us a report on how it did or didn't work out for him.

Of course it turned out to be worthless for that purpose, the guy bytched not only to us but badmouthed us in Australia claiming that we'd burned him.

It was a lesson well learned about human nature. A mistake like that never happened again.

Too late Dave. I've been already gone mad. *LOL*

Where is my mental doctor? Where is my good stuff medication (the colored pills)?
Doctor!!!!!! Mental Doctor pleaaaaaaaaaaaseee!!!!!!

Aziz

[Jose]

Daverave
The photo shows only one of the coils, remember that they are two and are connected in series.
The two coils are constructed identically, the only difference is its diameter.
The inductance of the higher coil is 175 uH and 1.2 ohms.
The inductance of the smaller coil is 100 uH and its resistance is less than 1 ohm.
Connected in series and the coil arranged girl inside the large coil, gives an inductance of 380 uH and 2 ohm
These values are approximate, since my instruments are not accurate.
Do not understand the last question.
You can experiment with a single coil of three turns cat6, and diameter 25 cm (10 inches). You will have 8X3 .. 24 laps and an inductance between 300-350 uH with a resistance of about 1.5 ohms.
Also this type of coil is easy to make and you answer quickly, use less tin solder candidad possible so as not affect their response.
Regards
Jose