Whites Surf PI schematic

[DOOLEY]

hello Ashkelon,

NO.........
values of C4 / R12 are just fine,

experimented with changing the values in the past,
and,
although not TO critical, 10k and 100nf seen to work the best.


as I said, base line fluctuation at the pre-amp output is normal,
earth field removed by the next stage.

measure D.C level at the output of the op-amp on the next stage,
earth field, or small non metallic magnet should have NO ( or little ) effect.

however,
nearby interference may still be there.

indoor environments can be electrically quite noisy.

mains electric, fridge motors, florescent lights, battery clocks ( esp these !! dam you battery clocks !! ) LOL.

[ashkelon]

hello Ashkelon,

EARTH MAGNETIC FIELD is everywhere................ ( even inside house !! )



in your last video, that is most DEFINITELY earth magnetic field you are seeing.

going to guess your testing at the output of the pre-amp ??
this is normal.

magnetic field effect on the base line is REDUCED after the C4 / R12 filter.

it's the following stage ( 4066 sample switches and integrator that remove the earth field )
( hopefully....... )

Thanks Dooley, Must i replace the bigger value r12 = 20K c4 = 200N ?

[DOOLEY]

hello Ashkelon,

EARTH MAGNETIC FIELD is everywhere................ ( even inside house !! )



in your last video, that is most DEFINITELY earth magnetic field you are seeing.

going to guess your testing at the output of the pre-amp ??
this is normal.

magnetic field effect on the base line is REDUCED after the C4 / R12 filter.

it's the following stage ( 4066 sample switches and integrator that remove the earth field )
( hopefully....... )

[ashkelon]

I do not recognize this board can you show the schematic?

mostly all of their same schema

[Old cart]

0V line moving as flag when i shake coil, is every surf pi same ? there is no metal and electromagnetic field in here

https://youtu.be/1sTIqrEul_w

I do not recognize this board can you show the schematic?

[ashkelon]

my surf pi problem

0V line moving as flag when i shake coil, is every surf pi same ? there is no metal and electromagnetic field in here

https://youtu.be/1sTIqrEul_w

[ashkelon]

my surf pi problem

0V line moving as flag when i shake coil, is every surf pi same ? there is no metal and electromagnetic field in here

https://youtu.be/1sTIqrEul_w

[Old cart]

Here you can download unzipped FatBob's Express (.sch format) schematic:

http://www.filedropper.com/surfpipro


Thanks both to your kindness!

Thank you WM6. This appears to be SURF PI PRO. That is not a bad thing but for my purposes I will modify. Let me take a look, Thanks so much FatBob

[ashkelon]

it would have 16 volts/ 1.33K across i so 16mA so 144mW so I probably won't burn but it will get quite hot. This circuit seems to have problems. If you can I would avoid it.

yes it did not burn, i tryed quickly, there is no good output shape 5534 pin 6 for sample

[Old cart]

i think so , U108B pin7 out 4V must connect these pins but R110 1K may burn

it would have 16 volts/ 1.33K across i so 16mA so 144mW so I probably won't burn but it will get quite hot. This circuit seems to have problems. If you can I would avoid it.

[WM6]

Thank you. I don't have an (un) zipper here so I will look at it later. Did you draw this from scratch?

Here you can download unzipped FatBob's Express (.sch format) schematic:

http://www.filedropper.com/surfpipro


Thanks both to your kindness!

[Koala]

i don't think that it's so thin.......it has about 7 mm
https://www.google.ro/search?q=gold+...HZc92fFThoM%3A

I don't have a 7mm chain to try. Any distance I give would be guess work. However it only see a target the size of one link so unless it has a large clasp it want be a large distance.

Adjusting the delay for gold does have a negative affect on other targets

[ashkelon]

i think so , U108B pin7 out 4V must connect these pins but R110 1K may burn

[Old cart]

Can you please write the voltage values 1-2-3 numbered at picture ?

Relative to ground the voltage is 0. Relative to the minus side of the battery it is plus 4 volts. Just looking at the circuit it seems there may be many design problems. It may work but maybe not very well or very long.

[ashkelon]

Can you please write the voltage values 1-2-3 numbered at picture ?