My Surf PI works - thanks Silverdog and ApBerg

[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?

[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.

[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

[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:

[Majarit]

HI there

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

Thanks

[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

[ApBerg]

Hi App

Thanks for your ongoing help. I hooked up the scope and started to understand the circuit better, and my delay/tr looks the same, the delay pot does the same as yours.



I disconnected the TUNE and OFFSET and managed to detect the gold ring at about 80mm. So I made two more coils;

PVC; 214uH - 1.6Ohm
Brown hookup; 267uH - 2.5Ohm
enamel; 282uH - 1.6Ohm

But much the same results, I'll study coil making tomorrow and try again.

Here are some pictures of the case anyway, not ready for water testing yet but not far off.

Thanks,
Ant

Hello Ant,

You have done a lot work... nice control panel ! Do you have special potentiometers for it that are waterproof ?
Your detectors sens. is to low , if al is ok it must detect over 25 cm, I am shure you wil get that.

Regards.

Ap

[ant]

Hi App

Thanks for your ongoing help. I hooked up the scope and started to understand the circuit better, and my delay/tr looks the same, the delay pot does the same as yours.



I disconnected the TUNE and OFFSET and managed to detect the gold ring at about 80mm. So I made two more coils;

PVC; 214uH - 1.6Ohm
Brown hookup; 267uH - 2.5Ohm
enamel; 282uH - 1.6Ohm

But much the same results, I'll study coil making tomorrow and try again.

Here are some pictures of the case anyway, not ready for water testing yet but not far off.

Thanks,
Ant

[ApBerg]

..... with the delay pot you set the sample window's: the 4093 pin 3 and 4 close the switches from the 4066 in time shift , the LM 358 can now see the 'receive signal' coming from the NE5534 at 2 different time's .. this lets the detector know if there is "anything" in the receive signal. So the delay pot is imported the fist window to close to the transmitpuls give's some problems.... to far less sens.
Wel look at the scope samples ... hope this helps ..

Best regards.

Ap

[ApBerg]

Hallo Ant,

To be shure that things indeed work ok I have made some checkings.
If you leave out the tune pot (and think the offset pot) the surf detects a ring as on the photo at some 15 cm. With the tune pot in place and at max ( just getting threshold ) it is 25 cm + 'Look at the coil, normal isolated wire some 20 turns (I think) works good.
The most importend adjustment is the delaypot.... look next message...

[ApBerg]

So i got home from work and decided to switch boards for the second one I got. Working much better, no problem with the tune dial. I think I just need to work on a better coil and hopefully get more depth, only getting about 5-10cm for a (au) $1 coin.

So back to the old board, I've checked all the cap and resistor values against the bom, and Aps diagram, next I'l try swapping the IC's, but that can wait for another time.

Anyway tea's ready, thanks for everyons help

Hello Ant,

You must detect wedding rings and medium size coins in the 20 cm+ range...good to tray a different coil.... you have some info on the coil you use now ?

At the and it will work ok !!

Regards.

Ap

[ant]

mmmmm

So i got home from work and decided to switch boards for the second one I got. Working much better, no problem with the tune dial. I think I just need to work on a better coil and hopefully get more depth, only getting about 5-10cm for a (au) $1 coin.

So back to the old board, I've checked all the cap and resistor values against the bom, and Aps diagram, next I'l try swapping the IC's, but that can wait for another time.

Anyway tea's ready, thanks for everyons help

[ant]

Hi again Ap

Just saw your post at http://www.geotech1.com/forums/showp...2&postcount=29, Thanks, should help when I get home I'll check my board.

[ant]

Hi Ap

Thanks for your help so far. I didn't get a chance to have another look yesterday. I do think there is something wrong, the TUNE dosen't work as you describe. The pots are mounted off the board with wires, but I also tried mounting the pot on the board with the same results. I think i'll have to check each component against the schematic

It does generally work, it can detect my metal ruler at about 20cm, a gold (white gold is all I have) ring at about 5-10cm. Considering I'll only be using it for diving (not scuba) maybe that will be good enough cause I don't want to dig too deep underwater anyway

Anyhoo, I'll have another look at it tonight.

Thanks,
Ant

[Rov]

Hi Ant,think you from Oz? am I correct.Im also here,so if you have an issue with your build/construction,give us a quick pm.an I may be able to help you.
regards rov