[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 4    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 Lord Dracon
Bronze Member
*

Join Date: Apr, 2011
Thank you8

Activity
0%
Male
United Kingdom
Posts: 233
Referrals: 0

1200.00 Gold
View Inventory
Linux
Linux
Chrome 44.0.2403.133
Chrome 44.0.2403.133

Awards

Dario MD-3006SS VLF / SURF 1.2 PI (WIP) / Garrett Ace 300i
« Reply #30 on: August 14, 2015, 04:41:08 pm »
Go Up Go Down

I was thinking 2 in 1 ... if does not work mebe pin pointer will have t be in the arm rest.


Linkback:

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

http://www.thunting.com/smf/index.php/topic,60476.msg300208.html#msg300208




Logged

Keep searching ... you might just find it.

Happy Hunting Detecting

Offline Lord Dracon
Bronze Member
*

Join Date: Apr, 2011
Thank you8

Activity
0%
Male
United Kingdom
Posts: 233
Referrals: 0

1200.00 Gold
View Inventory
Linux
Linux
Chrome 44.0.2403.133
Chrome 44.0.2403.133

Awards

Dario MD-3006SS VLF / SURF 1.2 PI (WIP) / Garrett Ace 300i
« Reply #31 on: August 17, 2015, 01:32:46 am »
Go Up Go Down

  Rider   Mad  Rider oohh my SurfPI kits should be arriving today/tomorrow... I sure hope its today....!soo excited!  Rider  Mad  Rider
 
  Pray  Detecting      Laola         Laola    Pray  Detecting

Linkback:

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

http://www.thunting.com/smf/index.php/topic,60476.msg300262.html#msg300262




Logged

Keep searching ... you might just find it.

Happy Hunting Detecting

Offline Lord Dracon
Bronze Member
*

Join Date: Apr, 2011
Thank you8

Activity
0%
Male
United Kingdom
Posts: 233
Referrals: 0

1200.00 Gold
View Inventory
Windows NT 10.0
Windows NT 10.0
Chrome 103.0.0.0
Chrome 103.0.0.0

Awards

Dario MD-3006SS VLF / SURF 1.2 PI (WIP) / Garrett Ace 300i
« Reply #32 on: July 09, 2022, 03:45:14 pm »
Go Up Go Down

Sorry for digging up an old thread, but i've just started getting back to where i left off in 2015, it been a mad few years... I hope you are all keeping well.

Well, I eventually built the coils I had invisioned in my head and they worked surprisingly well (2 concentric coils.) 1x 9.5" Dia and 1x 4" dia connected in series.. I literally just read Homefires link to the patent .. whaa .. someone beat me to it.  Violent .. wish i had read and understood this in 2015 Angry . The only diffrence between my design and the patent is the Damping resistors, which i did not insert .. that might explain the ringing when passing over an object .. there was me thinking it was just a threshold issue i was experiencing and was having trouble trying to correct/get rid of...

Well I now know to insert a couple of damping resistors, this should clear up the noise. (the issue of not having an oscilloscope.. yes i've still not bought one  Grin - someone i know had one connected via bluetooth to his mobile .. a tiny kit .. but works great .. anyone else have experience of these? ). Anyhow i'm still wondering whether the damping resistors will affect detection depth (something i need to test as currently getting great detection on a small gold earring at 11" in air and a gold ring at 15")

What is the formula for calculating the 2 damping resistors (one before each coil going to ground). I'm thinking that the resistors are calculated using the ratio of the impedance of the two coils, a bit like a voltage divider. But then I suppose capacitance also comes into the equation. However, to hazard a guess i would say the total resistance of the coil circuit needs to be equilavent to that set out in the plans for the coil of approx 1.3 ohms .. therefore resistors in parallel should also all add upto this including the resistance of the wire. hopefully i'm going along the right track. (thinking aloud), any advice would be appreciated.





Linkback:

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

http://www.thunting.com/smf/index.php/topic,60476.msg335298.html#msg335298




Logged

Keep searching ... you might just find it.

Happy Hunting Detecting

Offline nickel_n
Mod
Gold Member
*****

Join Date: Jan, 2009
Thank you363

Activity
3%
Male
Australia
Posts: 2796
Referrals: 0

6190.00 Gold
View Inventory
Windows NT 10.0
Windows NT 10.0
Firefox 102.0
Firefox 102.0

Awards

MXT All Pro,EagleSL,Spectrum,XLT,DFX.Garrett Seahunter markII,SD2000,GT16000
« Reply #33 on: July 10, 2022, 04:44:40 pm »
Go Up Go Down

good read for PI coil and how to work out damping resistor

Linkback:

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

http://www.thunting.com/smf/index.php/topic,60476.msg335305.html#msg335305



There are 1 attachment(s) in this post which you can not view or download

Please register for viewing them.

Making aFastPulse Induction Mono CoilAPractical How.pdf


Logged

The Diggers Oath
We swear by the Southern Cross to stand by each other and fight to defend our rights and liberties.

Offline Lord Dracon
Bronze Member
*

Join Date: Apr, 2011
Thank you8

Activity
0%
Male
United Kingdom
Posts: 233
Referrals: 0

1200.00 Gold
View Inventory
Linux
Linux
Chrome 103.0.0.0
Chrome 103.0.0.0

Awards

Dario MD-3006SS VLF / SURF 1.2 PI (WIP) / Garrett Ace 300i
« Reply #34 on: July 11, 2022, 10:55:02 am »
Go Up Go Down

Great document.. what a read!..  looking at the project, I really need to invest in a cheap and reliable oscilloscope.. going to be stuck until then.. my coil design/parameters cannot be that far off if it is able to detect smallish gold without damping resistors... just a bit noisy that's all.. hard to adjust threshold to keep noise down. (That might be the ringing on the coil I'm getting outputted to audio)
Anyone have any advice for a cheap oscilloscope (self build kit is an option if it makes it cheaper). I have heard of Bluetooth ones that connect via android are they any good or better to get standalone?
All advice is appreciated.

Linkback:

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

http://www.thunting.com/smf/index.php/topic,60476.msg335306.html#msg335306




Logged

Keep searching ... you might just find it.

Happy Hunting Detecting

Offline Lord Dracon
Bronze Member
*

Join Date: Apr, 2011
Thank you8

Activity
0%
Male
United Kingdom
Posts: 233
Referrals: 0

1200.00 Gold
View Inventory
Linux
Linux
Chrome 103.0.0.0
Chrome 103.0.0.0

Awards

Dario MD-3006SS VLF / SURF 1.2 PI (WIP) / Garrett Ace 300i
« Reply #35 on: July 11, 2022, 01:35:54 pm »
Go Up Go Down

I was thinking of getting an oscilloscope that my budget allows, something like this...

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

https://www.ebay.co.uk/itm/134067688869?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=O6qeelW4SxS&sssrc=2349624&ssuid=s0TFiOgrTrq&var=&widget_ver=artemis&media=COPY


Comments welcome.. (mods please delete post, if this type of post is not allowed.. no misuse intended.just advice required.. thanks)

Linkback:

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

http://www.thunting.com/smf/index.php/topic,60476.msg335307.html#msg335307




Logged

Keep searching ... you might just find it.

Happy Hunting Detecting

Offline nickel_n
Mod
Gold Member
*****

Join Date: Jan, 2009
Thank you363

Activity
3%
Male
Australia
Posts: 2796
Referrals: 0

6190.00 Gold
View Inventory
Windows NT 10.0
Windows NT 10.0
Firefox 102.0
Firefox 102.0

Awards

MXT All Pro,EagleSL,Spectrum,XLT,DFX.Garrett Seahunter markII,SD2000,GT16000
« Reply #36 on: July 11, 2022, 02:37:09 pm »
Go Up Go Down

its all good with the post  Smiley
but looks like that for the same price or there about you can get an older analog scope from eBay.
i think will save you a lot of trouble
look also here:

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

http://www.thunting.com/smf/metal_detectors/help_with_pc_sound_card_oscilloscope_needed-t18762.0.html;msg122385#msg122385



Linkback:

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

http://www.thunting.com/smf/index.php/topic,60476.msg335309.html#msg335309




« Last Edit: July 11, 2022, 02:46:27 pm by nickel_n »
Logged

The Diggers Oath
We swear by the Southern Cross to stand by each other and fight to defend our rights and liberties.

Print
Pages:  1 2 3 4    Go Up
Jump to:  

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