Underwater PI detector

[Geo]

Hi.
I want to look a wreck.
Who detector is better so to construct it??? Barracuda or Whites Surf PI???

Regards

[nickel_n]

For someone of your caliber you should do both.
And please show as how you are going to waterproof the pots.

[WM6]

Hi Geo

What have you in mind when you say "better".

If this regard to depth in general from PI detector with more power consuption you can expect a little more depth (Barracuda take more power).

But depth in this case will depend mostly on coil construction.

No one of both detectors are capable to discriminate.

For both (Geotech member) silverdog offer kits (PCB + electronic parts), but PCB for Surf PI is specially designed to build underwater (tube) detector.

If silverdogs Surf PI kits are out of stock, I can send you one SUrf PI PCB (no parts) for free. Unfotunately I have no surplus PCB for Barracuda.

Happy diving

[Geo]

For someone of your caliber you should do both.
And please show as how you are going to waterproof the pots.

Several years ago built the baracuda but without good results. Now I see that they have constructed it many members with very good results.Now about how to make the potentiometer waterproof .... i don't know, maybe WM6 knows.....

[Geo]

Hi Geo

What have you in mind when you say "better".

If this regard to depth in general from PI detector with more power consuption you can expect a little more depth (Barracuda take more power).

But depth in this case will depend mostly on coil construction.

No one of both detectors are capable to discriminate.

For both (Geotech member) silverdog offer kits (PCB + electronic parts), but PCB for Surf PI is specially designed to build underwater (tube) detector.

If silverdogs Surf PI kits are out of stock, I can send you one SUrf PI PCB (no parts) for free. Unfotunately I have no surplus PCB for Barracuda.

Happy diving

Hi WM6.
With "better" i mean the depth. But now that i thinking better not so big problem with depth because i want to detect many ceramic jarsthat are upon the dredger.
So maybe the Surf PI is better because i can put it inside a thin plastic tube.
And now the problem...... how i can make the potentiometers waterproof at 30m depth or at 3 atm presure????
I am afraid that a seal (o-ring) at the outside of the potentiometer shaft is not enough.
Any idea...

Regards

[WM6]

I am afraid that a seal (o-ring) at the outside of the potentiometer shaft is not enough.
Any idea...

Regards

You can try with good perservative (condom) or children balloon. Fix perservative ring to panel (over potentiometer shaft) using silicone adhesive. Cause perservative is very elastic, you can manage potentiometer at desired position, without rotating shaft back. Rinse Rubber perservative in fresh water after use and care with glycerine.

[Geo]

Thanks WM6.
I am afraid that the solution of perservative (condom) or children balloon will not withstand at 3 atm presure...
But I have much time ahead of me in order to look for the right solutions...
I think that PVC is the best solution because there is very good glue for it...

[Carl-NC]

And now the problem...... how i can make the potentiometers waterproof at 30m depth or at 3 atm presure????

APM Hexseals

[Geo]

Thanks, but very big video....
What do you use at whites for surf PI???
Also can i use the coil of TDI at 20... 30 m underwater ???

[6666]

Geo there are a few threads here that show home made water proof MD's
this thread is one of many ideas.
use "pressure" PVC
look around post #17
http://www.geotech1.com/forums/showthread.php?16576-Led-output-for-Surf-PI

[Geo]

Thanks for info but they are not all so clear....
For example the coil has not shield..... and the system to make the potentiometer waterproof is a little difficult.
Also i need a good way to make the connector of coil from TDI waterproof.

Regards

[WM6]

Hi Geo, instead of using waterproof connectors, you can try this:
A little more soldering on coil change, but waterproof safe.

[DIRCEU]

Hi! Geo

I remember, long time ago ApBerg post something about waterproof potentiometers made by him in a lathe.

Best regards,

DIRCEU

[Fabian]

This is the link of the Apberg's potentiometers.

http://www.westfloridacomponents.com...ST+Switch.html

I bought several and used them in my first Baracuda. They are 12k instead of 10k, but work perfectly. I just had to make a small adjustment because the shaft is very small and got no knobs to put in them, but nothing special. Have an o-ring on the outside and one on the shaft and are made of stainless steel.

Regards,

Fabian

[Geo]

Hi Geo, instead of using waterproof connectors, you can try this:
A little more soldering on coil change, but waterproof safe.

[ATTACH]25979[/ATTACH]

WM6, seems good solution but i can't understand what you mean with laminate. Google translate don't help me

Hi! Geo

I remember, long time ago ApBerg post something about waterproof potentiometers made by him in a lathe.

Best regards,

DIRCEU

6666 gave the adress of this thread

This is the link of the Apberg's potentiometers.

http://www.westfloridacomponents.com...ST+Switch.html

I bought several and used them in my first Baracuda. They are 12k instead of 10k, but work perfectly. I just had to make a small adjustment because the shaft is very small and got no knobs to put in them, but nothing special. Have an o-ring on the outside and one on the shaft and are made of stainless steel.

Regards,

Fabian

Problem is not the potentiometer with the swich but the good instalation of o-rings.
Any way i will try some solutions.

Thanks