Whites Surf PI schematic

[seadoggy]

to sensitive mine does the same adjust it down a bit but also had falseing problems under water i was a dirty coil plug connection . turn all electrics off in the house very sensitive board. have no shielding in my coil just cheap 4 wire coil lead with silver shielding

How to solve that??its is really annoying!
i also try other coil same problem when i swing on right make sound

[soverey]

hello i make Surf PI!the board work good,but i have small problem when i swing with coil to right make false signals!any idea what can be??
i using coax cable with shield my coil is also shielded!
regards

I have a similar problem , I shielded my coil with cardboard spayed with graphite spray , but it still makes a sound when moved left or right. How did you shield you coil ?

[seadoggy]

I have a similar problem , I shielded my coil with cardboard spayed with graphite spray , but it still makes a sound when moved left or right. How did you shield you coil ?

I using alu foil + coax cable with foil inside,something is not good here!
I try use other cable with out foil same problem

[6666]

but it still makes a sound when moved left or right.

While we dont have all the answers , your description sounds a little like the earth field is not being cancelled , check that you have both sample pulses on the 4066, and check that the target signal is going to both inputs of the integrator.

[seadoggy]

While we dont have all the answers , your description sounds a little like the earth field is not being cancelled , check that you have both sample pulses on the 4066, and check that the target signal is going to both inputs of the integrator.

what i must do to cancel earth field??its is possible test with ferrite rod?
my coil is 0.350 mh
thx

[Qiaozhi]

what i must do to cancel earth field??its is possible test with ferrite rod?
my coil is 0.350 mh
thx

The Surf-PI incorporates Earth Field cancellation by default, You don't have to do anything.

U7A is the gate for the main sample, and U7B is the gate for the late (Earth Field) sample.
6666 is suggesting that you probe U7 pin5 with an oscilloscope to confirm the EF pulse is present.

[seadoggy]

The Surf-PI incorporates Earth Field cancellation by default, You don't have to do anything.

U7A is the gate for the main sample, and U7B is the gate for the late (Earth Field) sample.
6666 is suggesting that you probe U7 pin5 with an oscilloscope to confirm the EF pulse is present.

i dont have scope mate ,can be this solved in other way,i also try put trimpot in place of R6 dumping resistor same thing!!,only make sound when i swing with surf pi in right side

[kt315]

maybe you get interference trouble, so try retune PPS on even value to electric lines standart frequency in your country.

nice value is due 600Hz this is kinda universal value worldwide
60 * 5 * 2 or 50 * 6 * 2

for delta pulse choiced 100 PPS for 50Hz
120 PPS for 60Hz.

[6666]

only make sound when i swing with surf pi in right side

Thats odd, but you can check the sample pulses are getting to the intergrater with an audio amp, you should hear a tone, its crude but it is an indicator.

[kt315]

Thats odd, but you can check the sample pulses are getting to the intergrater with an audio amp, you should hear a tone, its crude but it is an indicator.

coil - shielded. good
cable - shielded. good
housing - ? not shielded. bad or good?

[seadoggy]

Today i make new Surf PI and new coil shielded but same problem(when swing to right make sound lol)
also i go out from my house its more stable but problem remain.
I dont know what is going on in left side no make sound only when swing to right.
Regards

[green]

Maybe a dumb question. If earth field is causing the problem would it make a difference if facing north, east, south or west when swinging the coil?

[seadoggy]

Maybe a dumb question. If earth field is causing the problem would it make a difference if facing north, east, south or west when swinging the coil?

In every side make sound to right when swing with coil!,it is normal that surf pi can detect small magnet??

[kt315]

a magnet is too ferrous =)

[seadoggy]

I make this board of surf pi
i cant upload image