Square coil on Aquapulse 1B?

[Tmxdiver]

Hi to all,

I'm looking for any informations about the possibility to use my PI Aquapulse 1B in connect with a square coil 1x1m (not for divinig).

Unfortunately exact technical specifications of Aquapulse 1B are not known, except resistance of the regular coils (enclosed) and power supply (2400mA/H, 9,8V).

How can I design the square coil (how many windings, which kind of wire, thickness, etc.)? and could generally such large coil be powered by this unit?

Best regards
Jakob

[1843]

Hi Jakob,
You have to know the inductance of the factory coil (eg 38cm loop). You can understand it by a inductance meter or simply count the number of its windings and tell us, we will tell you the number of turns for a 1m frame coil.

Best regards,
1843

[Tmxdiver]

@1843: unfortunately it is no possible to count the numbers of turns on original coil - it's molded as mostly coils. I will try to get the informations from the Aquascan Company or to measure it directly from the coil .. we will see how successfull I will be..

Best regards
Jakob

[RKC]

G'day,

One of the main reasons my Aquapulse MD is my favourite detector (apart from it being fully waterproof and bomb proof) is that I can use coils of any size with it (and can even make my own coils for it, that will actually work ... even though I know practically nothing about MD electronics).

I have the large Aquascan factory coil and the Aquascan probe http://img.photobucket.com/albums/v521/NZGOLD/Gold%20detectors/P1010020.jpg ... which are both excellent coils that suit most situations I come across detecting for gold here in New Zealand. I also have a larger coil (see following photo) made by Reg, that works very well with it, even though Reg made the coil specifically for one of my Goldquest SSs.
http://img.photobucket.com/albums/v521/NZGOLD/Gold%20detectors/4815d29c.jpg?t=1215654723

I also have a 1 meter square coil that I was surprised to find I can use with my Aquapulse. The 1 meter square coil is one I got with a Bulgarian MD kit I bought a few years ago, and I found it worked very well on my Aquapulse and all I had to do was simply change the plugs to suit. http://www.igkelectronics.com/otherproducts/md-807.htm.

I don't have much use for my 1 meter coil as I usually detect heavily vegetated areas ... but its good to know I have one to hand if a situation should arise where it could be of use. I’ve often considered I would like to try my Aquapulse (with the 1 meter coil) in Australia. I've previously tried my Aquapulse with the Aquascan factory coil in Australia and it will actually work ... with the sensitivity turned way down! So, it might work with my large 1 meter coil to get depth in the HOT Australian mineralized soil, while ignoring all the small targets.

My guess would be that you would have no problem with making your own 1 meter (40" by 40") square coil.

I noticed recently that an Aquapulse MD found a gold bar
http://aquascan.co.uk/news.html .
The fact that the Mel Fisher group is currently using an Aquapulse MD must be as good a recommendation as its possible to get for a brand of metal detector.

Regards,
Rob (RKC) ( http://www.nzgold.co.nz )

[Tmxdiver]

@Rob:

Thank you for the interesting statement und some new informations. I'am also very satisfied with my AQ1B even thougt I prefer this time for underwater searching a small but very fine working PI machine "Ebinger 720C". The reason for it: I'm diving a lot in flumes (German Alps) and small, unobtrusive gear is more advantageous.

I sent allready an inquiry at Aquascan Company - maybe I get some informations about the inductance of the factory coil and some additional details. If not, I will try to measure it by myself. As quick and dirty solution I can also try to adapt square coil which design I had found in this forum..

Best regards
Jakob

[Tmxdiver]

This is the answer to my question of Aquascan:

"I would suggest (by calculation) that you need between 10 & 12 turns of
multi stranded wire for your 1 metre square coil. Good luck with your
experiments and by all means share your experiences."

A nice gesture, I think. This company seriously cares about the customer.

Now I need only the recommendation of a wire thickness and can start my square coil project..

[NormanB]

Hi Diver,

I would build a 1mx1m testcoil with 14 turns of 0,5mm² wire.
Inductance: ca. 800 yH
DC-Resistance: ca. 2 Ohm

Best regards

Norman

[Tmxdiver]

@Norman:

nice to see you hier. Thanks for your proposal. I will launch this weekend a few tests and report..

Best regards
Jakob

[Tmxdiver]

Hi to all,

my prototype of square coil for AQ1B is ready (50x50cm) and was tested today. I am very satisfied with the results, especially because the detector works very stable. You can see the results of the present day in the picture below. I have used 12 wire cable as compensated loop. Resistance = 4.2 Ohm. Further tests follow..

Best regards

[RKC]

G’day,

What a wonderful versatile MD the Aquapulse is! I tried an 8” Eric Foster mono coil (originally from my Goldquest SS) on my Aquapulse and it appears to work extremely well. I’m looking forward to soon trying it out in the field.
http://img.photobucket.com/albums/v5...g?t=1219888471

Regards,
Rob (RKC) New Zealand

[nelson]

Hi
I also own this MD. Now i m trying to find out what batteries have inside, cause yestarday i measure it and i got 9.1 volts and after charged i got 9.8 volts. My charger is for Nicad batteries and this confuse me, cause i had understood that model AQ1A have Nicad batteries and AQ1B have Ni MH batteries inside. So if you or any one else can help, please let me know before opening the detector. The schematic will be of good help too.
About the coil, i have the 25 cms coil, that after measurements i got 1.8 ohms of resistance and 420 uH of inductance.
Finally i will like to share expiriencies with people that have used this MD.
Regards
Nelson

[Qiaozhi]

Hi
I also own this MD. Now i m trying to find out what batteries have inside, cause yestarday i measure it and i got 9.1 volts and after charged i got 9.8 volts. My charger is for Nicad batteries and this confuse me, cause i had understood that model AQ1A have Nicad batteries and AQ1B have Ni MH batteries inside. So if you or any one else can help, please let me know before opening the detector. The schematic will be of good help too.
About the coil, i have the 25 cms coil, that after measurements i got 1.8 ohms of resistance and 420 uH of inductance.
Finally i will like to share expiriencies with people that have used this MD.
Regards
Nelson

The Aqua Pulse AQ1B uses an 8.4V 2.2Ah Nicad battery pack. Looking through the small round holes in the top and bottom of the pack, I can see there are 7 C-type cells.

[nelson]

Yes, you are right Qiaozhi
I did oppened my AQ1B and i found the pcb very simple, like surfmaster or may be less complicated. I took a few pictures from inside and also the battery pack that is the one you are mentioned.
My detector seems to work fine, but there is only one thing i´m not shure if is normal or not and this is the way it start to detect, The audio when you start to reach a target, it goes like is unstable sound with variations in tones and sound like unstability, i mean that you don´t hear the tipical tac tac tac that goes faster when you aproch to the target. While you are close to it, the sound gets very stable and sound goes up with solid and strong signal. However, in my first test, it shows that can pick up targets very deep.
My first test where done on my house that is very very close to high power lines and this sound looks almost the same when i turn on my XR71, getting a very unstable signal but no lost of deep. So my next test will be away from power lines, cause i can tell you that this MD is very powerfull.
Now i m looking for schematics, to have a backup in case the machine fails

Regards
Nelson

[nelson]

Here are some pictures i took

[nelson]

Does anyone knows how AQ1B sound when it start to detect a target until is close to it?
Regards
Nelson