[x] Welcome at THunting.com!

A fun place to talk about Metal Detecting, Treasure Hunting & Prospecting. Here you can share finds and experience with thousands of members from all over the world

Join us and Register Now - Its FREE & EASY

THunting.com
Treasure Hunting & Metal Detecting Community
   
Advanced Search
*
Welcome, Guest! Please login or register HERE - It is FREE and easy.
Only registered users can post and view images on our message boards.
Did you miss your activation email?

Login with email, password and session length
Or Login Using Social Network Account
News:
Pages:  1 2 3   Go Down
Print
Share this topic on FacebookShare this topic on Del.icio.usShare this topic on DiggShare this topic on RedditShare this topic on Twitter
Tags:
0 Members and 1 Guest are viewing this topic.
Offline xavierTopic starter
Moderator
Platin Member
*****

From a rainy Brussels
Join Date: May, 2009
Thank you166

Activity
0%
Male
Belgium
Posts: 7339
Referrals: 0

32206.00 Gold
View Inventory

Awards
« on: August 01, 2011, 04:13:57 pm »
Go Up Go Down

Hi Guys

I'm looking for information regarding the construction of a spider web coil for example how many slots must there be? dose one calculate the amount of slots from the diameter of the coil? Are there any specific rules that one must follow in the construction? The reason I ask this is because I made a coil and it works very well but now I'd like to understand why this coil works so well.  (Did I just get lucky?)

All the best
Xavier

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,26821.msg189181.html#msg189181


Xavier


Logged

So many questions so little time

Offline GoldDigger1950
The Old Man and the Soil
Global Moderator
Platin Member
*****

Just call me GD.
The Old Man and the Soil
Join Date: Jun, 2009
Thank you225

Activity
0%
Male
United States
Posts: 11219
Referrals: 12

47848.00 Gold
View Inventory

Awards

Garrett Groundhog ADS, Garrett Sea Hunter, Bounty Hunter Tracker IV, Bounty Hunter Pioneer 505,Minelab Eldorado Mk II, Tesoro Compadre, Tesoro Tiger Shark & A Few Home Brew Detectors
« Reply #1 on: August 01, 2011, 04:17:41 pm »
Go Up Go Down

What are you defining as a spider web coil, Xavier?

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,26821.msg189183.html#msg189183




Logged

It's all about that moment when metal that hasn't seen the light of day for generations frees itself from the soil and presents itself to me.
Let's Talk Treasure!

Offline xavierTopic starter
Moderator
Platin Member
*****

From a rainy Brussels
Join Date: May, 2009
Thank you166

Activity
0%
Male
Belgium
Posts: 7339
Referrals: 0

32206.00 Gold
View Inventory

Awards
« Reply #2 on: August 01, 2011, 04:24:44 pm »
Go Up Go Down

OK well you see the coil that they use in the radio receivers and TX antennas well that the one perhaps I should just post a photo of the one that I put together 

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,26821.msg189184.html#msg189184


Xavier


Logged

So many questions so little time

Offline GoldDigger1950
The Old Man and the Soil
Global Moderator
Platin Member
*****

Just call me GD.
The Old Man and the Soil
Join Date: Jun, 2009
Thank you225

Activity
0%
Male
United States
Posts: 11219
Referrals: 12

47848.00 Gold
View Inventory

Awards

Garrett Groundhog ADS, Garrett Sea Hunter, Bounty Hunter Tracker IV, Bounty Hunter Pioneer 505,Minelab Eldorado Mk II, Tesoro Compadre, Tesoro Tiger Shark & A Few Home Brew Detectors
« Reply #3 on: August 01, 2011, 04:34:53 pm »
Go Up Go Down

Is that the flat coil wound in an ellipse on a form that has radiating legs?

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,26821.msg189187.html#msg189187




Logged

It's all about that moment when metal that hasn't seen the light of day for generations frees itself from the soil and presents itself to me.
Let's Talk Treasure!

Offline xavierTopic starter
Moderator
Platin Member
*****

From a rainy Brussels
Join Date: May, 2009
Thank you166

Activity
0%
Male
Belgium
Posts: 7339
Referrals: 0

32206.00 Gold
View Inventory

Awards
« Reply #4 on: August 01, 2011, 04:42:30 pm »
Go Up Go Down

Well yes but this one is round. I have been searching the net for more info on this type of coil but I keep finding sites for the radio am's and nothing in particular about it's design.

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,26821.msg189192.html#msg189192


Xavier


Logged

So many questions so little time

Offline shortribs
Bronze Member
*

Join Date: Feb, 2009
Thank you7

Activity
0%

United States
Posts: 257
Referrals: 0

1445.00 Gold
View Inventory

Awards

Fisher-Whites-Garrett
« Reply #5 on: August 01, 2011, 04:47:02 pm »
Go Up Go Down

Xavier  Put us up a picture if u can. We can see what u r up against.. 

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,26821.msg189195.html#msg189195




Logged
Offline xavierTopic starter
Moderator
Platin Member
*****

From a rainy Brussels
Join Date: May, 2009
Thank you166

Activity
0%
Male
Belgium
Posts: 7339
Referrals: 0

32206.00 Gold
View Inventory

Awards
« Reply #6 on: August 01, 2011, 04:49:05 pm »
Go Up Go Down

I'm up against a coil that works much better than what I could have hoped for LOL OK will take a photo of it

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,26821.msg189196.html#msg189196


Xavier


Logged

So many questions so little time

Offline GoldDigger1950
The Old Man and the Soil
Global Moderator
Platin Member
*****

Just call me GD.
The Old Man and the Soil
Join Date: Jun, 2009
Thank you225

Activity
0%
Male
United States
Posts: 11219
Referrals: 12

47848.00 Gold
View Inventory

Awards

Garrett Groundhog ADS, Garrett Sea Hunter, Bounty Hunter Tracker IV, Bounty Hunter Pioneer 505,Minelab Eldorado Mk II, Tesoro Compadre, Tesoro Tiger Shark & A Few Home Brew Detectors
« Reply #7 on: August 01, 2011, 05:00:43 pm »
Go Up Go Down

Quote:Posted by xavier
Well yes but this one is round. I have been searching the net for more info on this type of coil but I keep finding sites for the radio am's and nothing in particular about it's design.

As a receiver coil, there is none better. As a radiating coil, forget it. The coil builds up a signal on the outer edges radiating horizontally. A scatterwound coil has no edge along the horizontal. For a TX coil, that is ideal. In a VLF/TR unit, that would work very well in combination.

Do you know where the term "rule of thumb" originated? It comes from the way a field is generated in a coil. If you imagine grabbing the coil with your left hand and extending your index finger and thumb in an L shape, you are able to understand how a field is generated. The current flow from positive to negative is from your palm into your fingers wrapped around the coil. Your index finger represents the voltage positive side of the coil. In an AC circuit, that's a temporary condition so you must be prepared to mentally switch it when required. The thumb indicates the field direction. In a flat coil like yours, it goes out of the side of each wire and each wire diminishes the previous wire's field strength. Instead of the theoretically huge field on the edge, you have a field that is diminished by its own windings. In a scatterwound coil, the signal is in every direction around the coil giving it the best possible strength with a minimum of interference by the other wires.

This is why a radiating AM radio transmitter antenna is wirewound in a scatterwind configuration and an AM receiver antenna is flat wound. The TX sends out maximum field in all directions and the RX antenna offers a huge number of windings to that field. Directional antennae are different and should be the subject of another post in a galaxy far, far away.

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,26821.msg189198.html#msg189198




Logged

It's all about that moment when metal that hasn't seen the light of day for generations frees itself from the soil and presents itself to me.
Let's Talk Treasure!

Offline xavierTopic starter
Moderator
Platin Member
*****

From a rainy Brussels
Join Date: May, 2009
Thank you166

Activity
0%
Male
Belgium
Posts: 7339
Referrals: 0

32206.00 Gold
View Inventory

Awards
« Reply #8 on: August 01, 2011, 05:07:04 pm »
Go Up Go Down

OK that all makes good sense but why then dose this coil work so well on non ferrous metals like gold and lead?

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,26821.msg189200.html#msg189200


Xavier

There are 2 attachment(s) in this post which you can not view or download

Please register for viewing them.

IMG_9768.JPG
IMG_9773.JPG


Logged

So many questions so little time

Offline GoldDigger1950
The Old Man and the Soil
Global Moderator
Platin Member
*****

Just call me GD.
The Old Man and the Soil
Join Date: Jun, 2009
Thank you225

Activity
0%
Male
United States
Posts: 11219
Referrals: 12

47848.00 Gold
View Inventory

Awards

Garrett Groundhog ADS, Garrett Sea Hunter, Bounty Hunter Tracker IV, Bounty Hunter Pioneer 505,Minelab Eldorado Mk II, Tesoro Compadre, Tesoro Tiger Shark & A Few Home Brew Detectors
« Reply #9 on: August 01, 2011, 05:26:04 pm »
Go Up Go Down

It works so well because your RX sensitivity is maximized. Had I replied with only that, your followup would have been why. I explained why so you wouldn't have to ask.

This isn't meant to be a debate as to whether or not a particular coil works, because it clearly does. What you asked for was an explanation. I offered one.

Remember our discussion about multi-node receiver coils? Each of those are flat wound in my experiments and the scatterwound TX coil is in the middle of the pattern. I have 8 coils ordered around one TX coil. Using a 32 bit processor, I analyze the return of each coil combining the results in the hopes of ultimately getting both an alarming increase in depth and an accurate analysis of the target itself. Lots of work to do on this one.

Linkback:

You are not allowed to view links.
Please Register or Login

http://www.thunting.com/smf/index.php/topic,26821.msg189203.html#msg189203




Logged

It's all about that moment when metal that hasn't seen the light of day for generations frees itself from the soil and presents itself to me.
Let's Talk Treasure!

Print
Pages:  1 2 3   Go Up
Jump to:  

Powered by SMF 1.1.19 | SMF © 2005, Simple Machines | Sitemap
Copyright THunting.com