Aquasound

[kt315]

In a message dated 3/1/2015 12:12:46 PM Mountain Standard Time, [email protected] writes:



The only transformer I know of on the Aquasound is the audio transformer to drive the headphones.
L and R mean Left and Right.


I just looked and you are right. But there has to be some other way then where the 18v or 12V was changed over to 52V as a power booster. It seems to me that someone in the past mentioned that they used a step up transformer to change the voltage like Teknetics did.

This is what someone said in a post in the past:
Yes, you are correct about the Aquasound. It is now hand built by a couple of very talented people. 52V to the coil in high power and 32 in low. Once you get the feel to tune it optimally then this machine sure goes deep...much deeper than anything I have used before...VLF...PI....Minelab PI.....'

Melbeta

[kt315]

try use this circuit for piezo

[kt315]

from Melbeta
Anatloy
I have some technical material on one older model of the Aquasound in my files. If you have some high resolution photos, of each side of the board, I could look at the board, and make some identification observations for you. I am assuming that the photos might be similar to my technical material. If so, I would try to help you. But my material is older unit, so it may not be relevant to a newer model.

But we would not know that unless we see what you have.

The older AquaSound was a pure TR detector, not a VLF, and it had no ground balance control to remove black sands. so it was designed for clean white sands. It was an high powered unit, having three voltages from the power supply, +5V, +12V, and +18V. The +12V was fed into the Tx side, and there was +18v fed into two transistors, and then into an unknown identity transformer, purportedly to come up with +52V for full power use.

I know what a lot of the parts were, but do not know what the transformer that was used as far as its identity. I believe the transformer stepped up the voltage around 3 times to get +52V.

Inside the Rx of the coil I understand there were some electronic parts, including two 2N2222 transistors.

I know you are able to draw up schematics, so I am guessing you have somewhat of a schematic by now. How about sharing what you have and I will see what I can do to give you what I have.

I have always had an interest in this unit. I know that George Payne did something similar his S/T unit with the transformer in that earlier Teknetics S/T model before he dropped the transformer due to water leaks.
Melbeta

[Altair]

I have rougly calcutated the coil inductance starting from Nautilus Patent:
TX: about 1500 + 1500 uH (with bucking reduction);
RX: about 4000 + 4000 uH.
Now a coil with different diameters can be calculated.

[kt315]

my mistake. this transformer is for piezo element, not for a speaker connection . so secondary part has more winding, because piezo 'needs high voltage'.
first issue is RIGHT.

http://kamrad-club.ru/-razdel-masterskaya/-sdelai-sam-metalloiskatel/112--metallodetektor-aquasound.html#comments

[dbanner]

Thinking about it some more, perhaps it's simply balancing the RX coil without any tuning cap, just naked, and looking for 0 degrees phase shift directly from the RX coil to the scope.

[dbanner]

However there is one caveat. No mention is made of whether the RX is tuned or left untuned while balancing for 0 degrees phase shift.

I ask this question because I know phase shift is frequency dependent, is it not?

So is it 0 degrees tuned or 0 degrees untuned?

Given the fact that this detector has feedback adjustment pots for both voltage and phase, I think the 0 degrees phase shift is with the tuning capacitor. But I'm not certain.

[dbanner]

Here again I'm reminded of tesoro coil balance by phase and not minimum residual voltage.

[dbanner]

Coil must be set at 0 degrees phase, very important when making the coil.

(According to the patent) "the coils are adjusted for 0 degrees phase shift of an impressed test signal from the tx coil, as received by the RX coil."

That's fancy language for saying that the coils are balanced by phase and not by minimum residual voltage.

[dbanner]

SLB (search loop balance) pots are ordinary 100k linear potentiometers. "R" and "C".

[kt315]

yup, also can take any ferrite ring and wind 150-200 plus 20-50 wire loops. on secondary take 0.4-0.7 diameter wire.

[dbanner]

Audio output transformer from junk pocket transistor radio, you can find those.

[kt315]

sorry, output transformer. it transforms a voltage in a current. then primary would be more, secondary less.

[Altair]

What transformer is being used on this pcb ? I would like to try source them.

jasonNZ,
the trasformer should have the following spec:
ratio 1:2+2;
primary: 25 Ohm
Secondary: 50 + 50 Ohm

I don't know more.

[jasonNZ]

What transformer is being used on this pcb ? I would like to try source them.