As I’m dealing with a system that resonate by its physical proprieties like length
The phase of the feedback is dependent on the position of the microphone and must be tuned to get the right or most amplitude
Adjacent nodes are 180 degrees apart so from a node to an antinode there is 90
Meyer pll use filter two if I remember well and it is 180 degrees phase relationship for locking
I even had to use a coil or capacitor in the feedback to get it to tune for sensed current since current and voltage at resonance are at 90 degrees so I had to add 90 to get to resonate… basically it won’t be needed to tune the microphone but the exact position must be tuned! So it get the right frequency… with the coils it always got a little imperfection since I was not buffering the output the feedback always had some small phase difference… I guess the only way to make it different was to buttering the output or the feedback so as to be able to tune manually the phase
Diameter has an effect of lengthening the cavity and can be calculated
However I found that the calculation for a gap in a cylinder would need some more numerical analysis to get the number but for a gap of 1,7mm the frequency radially may be 138khz for water
There is also the gap length frequency that may be relevant depending of the mode of the vibration
The more I dig into it more it seems to me is about physical resonance of water in the audio range
The feedback coil of Stan had some center tap with voltage applied 5v it reduces the sensitivity of noise… I wonder if it’s connected to a piezo on its secondary side… not sure anymore if it’s in the same core.. it could be a manner to isolate the sensor so the cell can work floating
I came up with an idea for this hydrophone that is simply a piezo made to be water prof by using some transformer varnish and place inside a metal enclosure to make it directional and less prone to interference… may not last forever by may be able to capture the signal.. there is specialized equipment for that… if in your good heart you are thankful for this information and you can buy one and send to me… please let’s waste less time…
I’m not sure if water will break but it will indeed resonate like hell and we are going to have lot of fun!
Resume the frequency will be tuned by positioning the electrodes and sensor… tuned to maximum amplitude
The correct frequency can be found changing the frequency manually to find the highest amplitude of the signal for that position later the phase is matched to get the maximum amplitude possible
Seems like a good plan? Anyone willing to help?
Ways to help:
Send money haha
Send hydrophone
Send some comments
To to my YouTube and watch all the videos from start to end, like comment and follow and share (watching entirely is important otherwise you actually make my algorithm worse as it won’t be detected as relevant if you only watch a few minutes from a long video… please this is not so hard next to what we’ve done in this last 17 years of hard work and spending time and money already gone that was really hard to get