Carl's fluxgate Mag.

[waynehof]

Bought the kit from Fat Quarters-
Ive built lots of kits-
Built the Mag but ive read that i should have a slow put put sound when turned on, I dont, its no sound. After rotating on e/w axis, facing east rotating like a propeller w inclination I get about 120hz tone. Ive worked on a lot of equipment cal procedures but cant get this thing to cal. Sensitivity is very poor also, have to get about 10inches from my car to get tone change after cal.
Have Fluke scope & know how to use it. Any common problems that keep this thing from turning on with the common put put sound- IE mine is totaly silent when turned on.
Thanks

[damiafix]

I've the same problem, I'm checking the connections and the components. The real problem is to align perfectly the two fgm3 sensor.

Cheers, D.

[Geo]

I had the same problem when the align was bad.
When i aligned it good, i had very good sensitivity. Now it is again bad

[damiafix]

Hi Geo, could you to be most detailed?
Please could you show with a short video, the gradiometer in action, from the startup, the calibration phase, at the pratical use?
In this forum there are most people that, reading about the good and not much expensive project of Carl, have bought this kit from Speake, but with bad or nonexistent results!
I've spent much hours to recheck the circuit, the alignment of the FGM3 sensors but still give bad results!
Yes, I'm sure that this depend from my inability, but from the people that have realized this gradiometer and use it with success, we don't have received much help, this is objective!
This is a forum, or I'm forgetting something? I can not believe that over 1700 people, that have read my 3d, don't have the answers to my/our problems.
This criticism not is directed primarily at you, but involves everyone.
Only Chris have showed sensibility, spite don't speak english and don't have built this specified magnetometer!!!
Much questions, much doubts....few, and not clear, answers!

Returing to the gradiometer, there is not much clarity about the high sensitivity mode of the SCL007, I've read in this forum that the SCL007 don't permit a good balance of the sensors when work in high sensitivity mode, but PIN1 of the IC is connected to 5 volts through a 4.7kohm resistor. What is the treshold value for to swith from low at high sensivity mode? The circuit of default work in low or high sensitivity mode?

Many thanks for your reply, and I'm sorry for the vent, in a so bad english

Best regards, Dam.

[nahok]

Hi Damiafix;
I have read posts I agree with you.
There is a solidarity in the beautiful FGM3 gradiometer.
I bought this kit,
At the end of installation, but I could not do the calibration.
I was stuck where you inserted.
now
http://www.geotech1.com/forums/showt...highlight=fgm3
I check in your topic, I'll do.
I wish the work facilities.
Best regards.