Surf Pro Kit

[dime196604]

So, started this post and detector almost two years ago. Well life got busy and i got sick of messing with the surf pi. It sat back of the closet for a little over a year now, pulled it out last week ti give it another go. Originally i made a basket coil, that would only detect steel about 4in. Any coins was only 1in if i was lucky. So thats why i thought the detector was not working proper. So last week i threw together a cheap wire bundle coil about 220uh I used stranded wire about 3X as think as the inner strands of phone wire. Thought this wire would be too think. BUT the detector is alive now. I can detect a US penny at about 14in air test. US quarter at 15 and my gold wedding band at 12in. So needless to say the detector is alive and i am very happy with the outcome so far. Still gotta tune the damping to the coil yet but so far results are good. All this trouble shooting i did so long ago was for nothing. All it was, a crapy coil. If only i would have made one a year ago.

[dime196604]

Can I use copper braid from high quality coax as my shield? Been reading lot about shielding on the forum but no real answers. Some say this some say that. People say to use graphite powder and other day munu's only use it to cut on cost and that there is way better shielding material to use

[Tibuck19]

Can I use copper braid from high quality coax as my shield? Been reading lot about shielding on the forum but no real answers. Some say this some say that. People say to use graphite powder and other day munu's only use it to cut on cost and that there is way better shielding material to use

If you used 26AWG to bigger, there is no need for shielding the coil. unless you plan on detecting near homes, that has a lot EMI interference, besides, The surf Pi is more of a beach detector anyways right!

[kt315]

Can I use copper braid from high quality coax as my shield? Been reading lot about shielding on the forum but no real answers. Some say this some say that. People say to use graphite powder and other day munu's only use it to cut on cost and that there is way better shielding material to use

yes, if you do low speed coil. not, if you do high speed coil. choice what coil you do.

[dime196604]

For now I'm just going to leave it un-shielded, see how it goes and go from there. I will just wait to glass up the coil until i decide to us e a shield or not.

[qute1]

Most importantly ensure that whatever coil you make is tightly bound because loose coil windings (even just a little and yes they often "look" ok) cause the majority of "mystery" errors on this forum, the coil integrity IS the most critical factor of any md especially PI's.

[dime196604]

Well, I'm gonna use it a litttle before potting it. But the coild is wrapped tight with inner stands of para cord as tight as I could. Talk about making your hands cramp up. Then wound with electrical tape. I don't think any of the wires have any chance of movment.

[waltr]

Even bound tightly the whole coil could move or distort at the end to the swing.

Try tapping on the coil very lightly with a wood stick. If detector sounds off when tapped then it is a coil movement issue.

I do have this issue with my DIY concentric coil on a PI detector if I bump it into objects while sweeping. It is an un-potted coil held together with tape so not that surprising.
It doesn't happen that much so easy to live with and I like how this coil works.

[dime196604]

Can anybody walk me thought the process of finding out what the pulse delay of my coil is? I have a old scope with one working channel. Problem is i don't know my way around a scope too well. Only thing i have used it for is measuring AM modulation of my transceivers, and the damping resistor of my MD. So i i have no idea where to probe the board or what to set the dials on my scope to. Any guidance would greatly be appreciated, and please enplane it to me like I'm stupid. Seems to be the best option

[Tibuck19]

Can anybody walk me thought the process of finding out what the pulse delay of my coil is? I have a old scope with one working channel. Problem is i don't know my way around a scope too well. Only thing i have used it for is measuring AM modulation of my transceivers, and the damping resistor of my MD. So i i have no idea where to probe the board or what to set the dials on my scope to. Any guidance would greatly be appreciated, and please enplane it to me like I'm stupid. Seems to be the best option

First thing you need to do is tightly wrap you lose bundle of wire to make it a coil, you can not tune your detect with your coil that way, Second task is to watch this https://www.youtube.com/watch?v=OQMnjaMSKn8 , it will teach you how to measure time with your oscope , which then , you will know the delay pulse you are setting the detector too. Another thing that will help you understand more, Which was suggested to me , and was very helpful is, Buy the book Inside the metal detector written by Geotech very own Carl and George. https://www.amazon.ca/Inside-Metal-D...metal+detector

[dime196604]

Could anyone tell me where on the board is the test point for measuring the delay ??

[Polymer]

Could anyone tell me where on the board is the test point for measuring the delay ??

Not sure which kit you have, but on the Surf PI longboard 1.2 it is PIN 10 of the 4093 IC.

Knowing what schematic are you using would make it easier to know.

[dime196604]

Not sure which kit you have, but on the Surf PI longboard 1.2 it is PIN 10 of the 4093 IC.

Knowing what schematic are you using would make it easier to know.

It's the surfxx board

[Tibuck19]

Could anyone tell me where on the board is the test point for measuring the delay ??

Follow these steps all will be fine. http://www.adrianandgenese.com/blogg...rom-a-diy-kit/

[dime196604]

Follow these steps all will be fine. http://www.adrianandgenese.com/blogg...rom-a-diy-kit/

Thanks but that part is done. In just looking to figure out how to measure the pulse delay just to know where I'm at.