Built Fluxgate mag by Carl Moreland but have trouble

[xceed]

Hi all,
I bought from Speake & co the kit and built the Fluxgate MAg (gradiometer) by Carl Moreland. I did not use his gidelines to attach the fmx sensors, but the one described by Becker in his project (glued to a v-shaped aluminium rod.
Al was monted correctly (I think) , put the battery, powered on, no sound whatsoever, no matter what I do, turn it around, move the potentiometers, . In fact there is a small chirp, but that's all.
Could anyone give me some advice on what should I check?
The only anomaly I found during the install was that when I glued the sensors with the hot glue, because of the heat, the sensor exterior plastic box dilated a little.
Many thanks

[Altra]

Hi Xceed,

Did you check to see if you have +5 volts on the outputs to IC5 and IC6?

If no check your wiring. Are IC5 or 6 solder in backwards?

If you have 5 volts on the circuit board, check to see if you have +5 volts at each FGM sensors.

If you have a frequency counter or oscilliscope check for a 50Khz to 120Khz 5volt square wave from the output of each sensor.

Recheck all your connections, one little mistake is all you need.

Good luck
Mark

[xceed]

thank you, I will check

Thank you for the advice, I will check these things.