My Surf PI works - thanks Silverdog and ApBerg

[ant]

Do you have special potentiometers for it that are waterproof ?

No, just a lot of lube, 'O'rings and silcon. I'm only going to be snorkling, no scuba, so the pressure shouldn't be to high, I'll have to test it out soon; could be a complete failure, but how else do you learn?

I'm still only getting 100mm on a ring, but I'll keep bashing away at it.

The small PVC one you have that you did the LED mod on, what depth do you get with that? The coil I have in my PVC one seems to be as good as any of the others I've made, so I'm trying to figure out if it's my coil/s or the circuit that is giving me problems.

I know you are not making any money on this, Silverdog has to be just breaking even on what it has cost him, so a big thanks to you for your ongoing support.

Ant

[Majarit]

HI there

Is it possible to use a minelab gpx (DD) coil for testing with de surf pi ?

Thanks

[ant]

Hi Ap and everyone

I went to Victoria's "Golden Triangle" for Xmas so haven't been able to post here for a while, I didn't find any gold either

Anyway, here are some pics of my PCB:

[nelson]

Hi micheal.

I will like to have those pictures if is posible. I f so could you send me an email to [email protected]
Also i will like to know if anyone can tell me if surfmaster coil, need to be shield?
In advance many thanks and happy new year.

Nelson

I have an original SURF Pi coil that I have opened up for experimental purposes ....im not sure if I am allowed to post pictures of it as it is an original whites coil ....If carl okays it I can post them here ...
just trying to help all the Surf pi builders

[Qiaozhi]

Hi micheal.

I will like to have those pictures if is posible. I f so could you send me an email to [email protected]
Also i will like to know if anyone can tell me if surfmaster coil, need to be shield?
In advance many thanks and happy new year.

Nelson

You can download the pictures yourself by right-clicking on the image.

[bernte_one]

multiple questions / unknown soldering pads

What should i connect to the "GND pad" under R5 maybe the housing of pi detector board?

The points TP1 and TP2 are for measuremnts or not?

My surf pi works but don´t get an continuing sound for example a beeb every 5 sec. or so.
Is it right?- i found no videos. At mine there comes a short sound when tuning (i think it is the right point) and i can detect euro coins at 15cm (i know it could be more but it is a problem of my coil). From other Pi detectors i know a clicking sound at right tunig point.

Can anyone Help?

[nelson]

Hi bernte_one.
Take a look to this test i have done with my first sufmaster i build
Regards
Nelson

http://www.youtube.com/watch?v=WsW4uu_Zf54

What should i connect to the "GND pad" under R5 maybe the housing of pi detector board?

The points TP1 and TP2 are for measuremnts or not?

My surf pi works but don´t get an continuing sound for example a beeb every 5 sec. or so.
Is it right?- i found no videos. At mine there comes a short sound when tuning (i think it is the right point) and i can detect euro coins at 15cm (i know it could be more but it is a problem of my coil). From other Pi detectors i know a clicking sound at right tunig point.

Can anyone Help?

[nelson]

Hi and thanks Qiaozhi
I just did it last year, so thanks a lot any way
Regards
Nelson

You can download the pictures yourself by right-clicking on the image.

[bernte_one]

put videos also here
http://www.geotech1.com/forums/showthread.php?t=17538

[Sean_Goddard]

Hi All, I've been working on one of Silverdogs excellent Surfmaster PI kits. We put a Whites dual field coil on it and after a little "tweaking" we now pick up an 18mm 18ct mens gold ring at around 14" (35cm approx) with a clear signal.

We also have access to a REAL Surfmaster which we will be probing tomorrow. SO...to help you ALL I will TRY to post as many 'scope screenshots as we can along with details of what point in the circuit they were taken side by side (Silverdog kit V Whites PI) for comparison.

Silverdog, might I suggest a 100nF across the 4066 AND the 4093 supply pins as I see a lot of "bounce" around there on some of the signals and it IS customary to decouple digital switching IC's anyhow as part of good design practice.

The flyback is around 250V pk=pk and this picks up VERY significantly into the sensitive stages of the detector, it might be worth adding an inductor in the supply rails to these chips (thus isolating the TX part from them) and adding a nice FAT electrolyic with a good low ESR. In fact splitting the supply rails and adding some good filtering might help a LOT!

I also think that building the board and leaving the trimmers off until LAST allows you to soak the board in CLEAN isopropyl alcohol for half an hour or so to remove ALL contaminants, then coating the board with conformal sealer goes a LONG way to making the Surfmaster a LOT more sensitive.

I might also suggest dropping the current IC sockets and using turned pin ones. The reason for this is that flux tends to creep up the legs and onto the contact areas thus causing noisy and intermittent connections.

MORE TO COME!!

[gcause]

Hi Ant,

Glad you got your detector working. I am still building my first SurfPI.

I was looking at your pictures and noticed the 100N cap above the 555 chip appears to be in the wrong place. I think it should be over to the right in the spare solder pad in the picture. I think it is called C16.

In the pictures Silverdog supplied the right hand pin on the cap appears to be in line with the pins on the large cap just above it.

I could be wrong as I am new to this and learning also. Perhaps some more experienced builders could look at the photos and check this.

Hope this helps.

Regards,

Grant

[silverdog]

Hi Ant,

Glad you got your detector working. I am still building my first SurfPI.

I was looking at your pictures and noticed the 100N cap above the 555 chip appears to be in the wrong place. I think it should be over to the right in the spare solder pad in the picture. I think it is called C16.

In the pictures Silverdog supplied the right hand pin on the cap appears to be in line with the pins on the large cap just above it.

I could be wrong as I am new to this and learning also. Perhaps some more experienced builders could look at the photos and check this.

Hope this helps.

Regards,

Grant

I think it looks ok, for a 5mm box cap
I think in an earlier picture I had used a green film cap and used the spare pad you refer to for the right leg, as the leg spacing on these is much wider

Silverdog

[6666]

it might be worth adding an inductor in the supply rails to these chips (thus isolating the TX part from them) and adding a nice FAT electrolyic with a good low ESR.

What values ?
thanks

[Sean_Goddard]

Try a few until you get best results for space / cost taken

[6666]

Thanks Sean
I will get out the junk box