Aquasound

[jasonNZ]

was looking over the schematic and the picture of the board, i would imagine some of the components have been updated ?

This looks like a Polystyrene cap thats polarised , in the schematic has it been substituted with a film cap ?


then noticed the cap the seems to be between resistor 48 and 56 ?


and then cap 19 seems to be extra compared to what was on the board ?

[dbanner]

This coil has very high flux density.
When balanced properly with the two feedback pots, it will go deep.

[dbanner]

Really, p-p voltage was not measured across the whole coil (at resonant cap terminals), if you do it voltage is about 52V!

Yes, spice measures peak to peak, but with centre tap coil is measured with reference to the ground. If you measure across the entire coil, the voltage is double!!!

[Altair]

...
Results:
- frequency: 17.748 KHz
- output p-p voltage: 26V
...

Really, p-p voltage was not measured across the whole coil (at resonant cap terminals), if you do it voltage is about 52V!

[Altair]

Great! So it works.I have several questions.First, what inductance/ number of turns/ coil diameter did you use.Secondly, what is the value of the tuning capacitor you used.I did not put 50k resistor from collector to other end of coil( I suppose this is for simulation of the two 100k potentiometers) when I tested my coil. I wonder if this is why my circuit don't oscillate.

51 + 51 turns on 228mm diameter with 0.5mm wire
Measured resistance: 3.6 + 3.6 Ohm
Measured inductance: about 1500 + 1500 uH
Capacitor: 10nF

[dbanner]

PCB is gigantic ridiculous large Godzilla. I don't have big copper board for this monster.
I must try to make layout smaller.

[dbanner]

dbanner,I have doing a rapid test with my TX coil, .... it oscillate with Aquasound circuit from first start!Respect original schematic there are the following differences:- no Buck coils connected- BC327 instead of 2N2907- two 47K resistors instead of 50K, 51K ones- power supply: 10V at 100 ohm resistorResults:- frequency: 17.748 KHz- output p-p voltage: 26V Coil is connected as indicated in my previous post #54, with exclusion of bucks.

Great! So it works.I have several questions.First, what inductance/ number of turns/ coil diameter did you use.Secondly, what is the value of the tuning capacitor you used.I did not put 50k resistor from collector to other end of coil( I suppose this is for simulation of the two 100k potentiometers) when I tested my coil. I wonder if this is why my circuit don't oscillate.

[Altair]

dbanner,
I have doing a rapid test with my TX coil, .... it oscillate with Aquasound circuit from first start!
Respect original schematic there are the following differences:
- no Buck coils connected
- BC327 instead of 2N2907
- two 47K resistors instead of 50K, 51K ones
- power supply: 10V at 100 ohm resistor

Results:
- frequency: 17.748 KHz
- output p-p voltage: 26V

Coil is connected as indicated in my previous post #54, with exclusion of bucks.

[dbanner]

Nautilus coils.... expensive!

http://www.relichuntersupply.com/NautilusDetectors.html

[dbanner]

Underwater coil plugs.

https://www.amazon.com/Waterproof-Connector-2Screw-Voltage-Bulkhead/dp/B07BK35YZF

[dbanner]

The coil plugs.

https://projectpoint.in/index.php?route=product/product&product_id=501711119279

[Altair]

...

1N60 diode on your last Sprint layout needs rotation 180 degrees.

You right!
Here the correction:

[dbanner]

I like the 1260x oscillator.
Simulation give more voltage on coil and seems me it have a better stability.

I made the 1260x tx circuit and tried it with my coil.

It works very good.

1N60 diode on your last Sprint layout needs rotation 180 degrees.

[Altair]

Altair, I made a coil 8 inches, with 4inch for feedback. 0.4mm wire 40-10-10-40. I tried with 10nF cap and with other cap values.
Does not oscillate with aquasound oscillator.

Same coil is working very good from start with Fisher oscillator both 1212x and 1260x. I tried both and they work very good. Peak to peak voltage is measured 36v~

I like the 1260x oscillator.
Simulation give more voltage on coil and seems me it have a better stability.

[Altair]

It could be due to not enough mutual inductance value.