Proton Magnetometer

[Baterista]

The method used to making the PCB was the Press'n'Peel, with good results.

[Baterista]

Part List updated.


Part list.txt

[Geo]

Ok, this is the link.

http://www.ngdc.noaa.gov/geomag/operobs.shtml

Thank you

[Baterista]

Had a small change in the relay unit, I used an NPN transistor (PNP in the original)
and looking at the photo, it seems that the author used another transistor, and not
the specified in the list of components (2N2613), seems to be a 2N2102 (NPN) ,
also in the scheme is indicated the use of an NPN.

[Geo]

No problem with the relay driver transistor. Its job is only to enable the relay.

From the other side yesterday i tested the magnetometer out at field.
No good results.
There is so much noise that makes difficult to hear the signal from object. As more the volume so more the noise. I was able to hear the signal only at low volume. So from today i must looking for finding the solution of the problem.
I"ll inform


Regards

[Baterista]

Hello Geo,you used a PNP? did not work for me.
This can decrease the noise, but I do not know at what price.

[Geo]

Hi.
At relay driver i use a npn , i don't use the schematic by huggard but a 555 timer with a npn transistor (i don't remember if i use normal transistor or darlikton)for turn the relay on.
Now about the capacitor ... i"ll try it with some different values. Did you try it ???

Regards

[Geo]

Hello Geo,you used a PNP? did not work for me.
This can decrease the noise, but I do not know at what price.

[ATTACH]25342[/ATTACH]

As i see the schematic all the transistors at polarisation circuit must be NPN. Try BC547...8..9

[Baterista]

Hi.
At relay driver i use a npn , i don't use the schematic by huggard but a 555 timer with a npn transistor (i don't remember if i use normal transistor or darlikton)for turn the relay on.
Now about the capacitor ... i"ll try it with some different values. Did you try it ???

Regards

yes I used the capacitor in the circuit, connected via a switch (on - of), and is so quiet it's scary, you can hear the drips in the kitchen sink.

[Baterista]

As i see the schematic all the transistors at polarisation circuit must be NPN. Try BC547...8..9

I used some BC 549, stayed good.

[Baterista]

Because the supplier did not provide the bobbin to the potcores (would have to buy
a package with 1000 bobbins, so the price would be of $ 300.00, really absurd),
I had to use another bobbin millimetrically higher producing a "gap" unwanted, taking
as a consequence the buying another potcore an higher value of permeability to compensate
the problem, this is not an ideal setup, but had no choice.

[Geo]

Hi Baterista.
Also i used other types of potcores with different permeability, so the turns are not the same as at article.
Maybe today to try the capacitor. Now i have much noise and when the volume is high there are microphone echos...
Congratulations for your project, you made very good work. I am very lazy to make so good projects: Lol:

Regards

[Baterista]

Hi Baterista.
Also i used other types of potcores with different permeability, so the turns are not the same as at article.
Maybe today to try the capacitor. Now i have much noise and when the volume is high there are microphone echos...
Congratulations for your project, you made very good work. I am very lazy to make so good projects: Lol:

Regards

Thanks Geo, always kind.

[Baterista]

To obtain the specified value of L1 and L2 was necessary to change the diameter and the original length of the coil, which was
47.62 mm x 71.44 mm (The result was 16.8mH and 11.4 ohms) for 50 mm x 50 mm, when the result was 20.8 mH and 9,3 ohms.
At first I used 24 AWG and 23 AWG in the second.
23 AWG is the value nearest 24 SWG.

[Geo]

My coils are 24mH and 10 ohm.
I did not try yet the solution with electrolytic capacitor so to reduce the noise, but to am sure i design a new pcb for another schematic of main amplifier.

Regards

Btw... when you will try your magnetometer out to field???